Have you ever wondered why a bag of crisps ( or potato chips ) expands on an aeroplane? It's all about air pressure.

The crisp packet was sealed at a lower altitude where atmospheric pressure is higher than at higher altitudes.

As a plane takes off and altitude increases, the atmospheric pressure outside the bag decreases, but the amount of air inside the bag stays the same. This means the air inside the bag now exerts greater pressure on the air outside, making it puff up.

The post Why Do Crisp Packets Puff Up at High Altitude? The Science Explained appeared first on Science Experiments for Kids.

Life on Earth depends on the light and heat from the Sun. While the warmth from the Sun gently warms you on a sunny day, the core of the Sun is a mind-blowing 15 million degrees Celsius ( 27 million degrees Fahrenheit), and the surface is 5500 degrees Celsius ( 10000 degrees Fahrenheit).

That's hot enough to vaporise any material from Earth instantly.

The outermost layer of the Sun's atmosphere is called the corona. It extends millions of miles into space and is made up of very hot, low density plasma. It's only visible to humans during a solar eclipse.

The temperature of the corona is hotter than the surface of the Sun ranging between 1 million and millions of degrees Celsius.

Why is the sun so hot?

The Sun's heat comes from the core. Under huge pressure and gravity, hydrogen atoms are forced together to form helium, releasing massive amounts of energy, which radiates outwards as heat and light. This is nuclear fusion.

Activities for learning about the Sun

Find out how the position of the sun changes during the day with a garden sundial.

Discover how shadows form and draw shadow pictures.

Make a simple model of a solar eclipse.

Discover the science behind a solar eclipse.

Science Buddies has some brilliant sun prints.

Find out the science behind everyday phenomena.

The post How hot is the Sun? appeared first on Science Experiments for Kids.

You've probably seen or experienced most of these common science phenomena before, but you may not have thought about why they happen. From sticking a magnet onto your fridge to colourful lights in the sky, we explain ten fascinating phenomena and offer ideas for learning more about each one.

Get ready to delve into the science that makes our world amazing!

1. Rainbows

What is a rainbow?

A rainbow is a multicoloured arc made when light from the sun passes through drops of rain or mist. To see a rainbow, you need to stand between the sun and the rain with the sun behind you.

How do rainbows form?

Rainbows happen when sunlight is refracted and dispersed in drops of rain or mist. Water is denser than air, so sunlight slows down as it moves from the air into a raindrop. Light reflects off the inside of the water droplet and is split up into its component colours because of their different wavelengths.

The colours of the rainbow, ordered from longest to shortest wavelength, are:

Rainbow science activities

Make a rainbow with a prism. If it's not a sunny day, you can do this with a torch and a prism.

Look for a rainbow in bubbles.

Learn about another scientific phenomenon, the moonbow!

2. Aurora Borealis

The Aurora Borealis ( Northern Lights ) is a display of colourful lights in the sky, seen in very northern parts of the world, such as Scandinavia, Alaska and Greenland. It's caused by charged particles from the sun interacting with the Earth's atmosphere.

Find out more about the Northern Lights.

Watch a time-lapse of Northern Lights in Alaska.

3. Photosynthesis

Photosynthesis is the process by which algae, plants and some bacteria use carbon dioxide, water and light to create oxygen and glucose. In plants, photosynthesis occurs in the chloroplasts.

Plants have several adaptations that help them make as much energy as possible through photosynthesis. Their leaves are thin with a large surface area, which helps them absorb as much carbon dioxide and light as possible, and roots that spread through the soil allow them to take in as much water as needed.

Photosynthesis science activities

Learn about chloroplasts and other organelles with a jelly plant cell model.

Find out why leaves are green.

Learn about the different parts of a plant with a plant dissection activity.

4. Lightning

Lightning is a giant spark of electricity in the atmosphere. It happens when electricity is discharged between clouds, from a cloud to the air or from a cloud to the ground.

You can demonstrate lightning by creating a tiny spark of static electricity with a balloon and a metal spoon.

5. Diffusion

Diffusion is the movement of a substance from an area of high concentration to an area of low concentration. The movement continues until the substance is evenly distributed throughout the available space.

Learn more about diffusion

Diffusion can be demonstrated easily by adding a little food colouring to a glass of water. Initially, the food colouring is concentrated in one spot and then spreads without stirring through the water.

You can also demonstrate diffusion with a tea bag in water.

6. Magnetism

Magnetism is a force that causes certain materials to be attracted to each other. Magnets produce a magnetic field, where other magnets and magnetic materials experience a force. Magnets have two poles - north and south.

The force between two magnets can be attractive or repulsive. Two poles that are the same repel, and two that are unlike attract.

Learn more about magnetism

Use magnets to race toy cars.

Make a mini magnet maze.

Create a compass with a magnet.

7. Cloud Formations

Clouds are droplets of water and ice particles floating at different heights.

Heat from the sun turns water on the surface of the Earth into water vapour, which rises, cools, and turns back into water again, forming a cloud. Clouds float because the droplets of water are very light, and there's a constant flow of warmer air rising under the cloud, keeping it afloat.

Clouds grow when more water droplets stick together. When a cloud is heavy enough, it starts to rain!

Clouds are classified depending on their altitude and appearance.

In Snackable Science, we used egg white to demonstrate different shapes of clouds!

8. Fossils

Fossils are the preserved remains of animals and plants that lived long ago.

Not all remains become fossilised, and it is actually quite rare. Most animal and plant remains decompose after they die ( or are eaten by scavengers), but if they are covered by sediment ( usually sand, mud, or lava ), they may become fossils.

Learn more about fossils

Set up a dinosaur dig activity.

Learn about different types of rocks with my Rock Lab!

9. Bubbles

Have you ever wondered why bubbles always form a spherical shape? The forces acting between the bubble molecules cause them to form a sphere, which encloses the most volume with the least surface area.

Learn more about bubbles

Use a bit of science trickery to make a square bubble.

Make a giant bubble!

Build a bubble snake.

10. Shadows

A shadow is a dark shape formed when an opaque object blocks a source of light. Shadows can be seen outside on sunny days. They change shape during the day as the sun’s position changes in the sky.

Learn more about shadows

Make colourful shadow puppets.

Watch time go by with a DIY garden sundial.

Are there any more science phenomena you'd like to know more about?

The post The Science Behind 10 Everyday Phenomena appeared first on Science Experiments for Kids.

Einstein Rings are a type of gravitational lensing in which the light from a galaxy or star passes a large object, like another galaxy or black hole, and is bent around it. If the alignment is right, the light appears as a ring around the large object.

The galaxy or black hole closest to the observer acts as a lens, bending the light from the galaxy further away.

More astronomy questions and answers

How big is the solar system?

How does the universe expand?

How old is the Milky Way?

What is the Big Bang Theory?

The post What are Einstein Rings? appeared first on Science Experiments for Kids.

Extreme weather is a weather event that is unexpected and significantly different from normal weather patterns.

Weather around the world is naturally variable, but extreme events are becoming more common and intense.

Extreme weather

• Can be a single short event or take place over some time.
• More intense than the average type of weather for the area and time of year.
• Often poses a significant risk to life or the environment.

Examples of extreme weather

• Hurricanes
• Heatwaves
• Flooding and heavy precipitation
• Drought
• Tornadoes

• Wildfires - although wildfires are not direct weather events, they are linked to extreme weather patterns, are more likely to occur during drought conditions and are exacerbated by strong winds.

What causes extreme weather?

Extreme weather events have many causes, both natural and human-made.

Greenhouse Gases

Burning fossil fuels releases greenhouse gases into the atmosphere, which trap heat like a greenhouse. Examples of greenhouse gases are carbon dioxide, ozone and methane. The trapped heat increases temperatures around the world.

Warmer Temperatures

A warmer atmosphere holds more moisture than a cooler atmosphere. This leads to heavier rain and more intense storms.

Warmer Oceans

Warmer oceans lead to stronger storms and hurricanes. Hurricanes get their energy from the ocean. Warmer water means more energy and stronger more destructive hurricanes.

Deforestation

Trees and plants absorb carbon dioxide, which helps stabilise our climate. The more forests are cut down without being replaced, the more carbon dioxide there is in our atmosphere.

El Niño and La Niña

El Niño and La Niña are climate patterns in the Pacific Ocean that can have a huge global impact on weather patterns. El Niño and La Niña are irregular events that occur every two to seven years. El Niño and La Niña are natural events, but their effects can be increased by climate change.

El Niño is when the normally cool water on the west coast of South America warms up. Warm water evaporates more quickly, leading to an increase in rainfall in South America and drought in Australia, Indonesia and South Asia.

The opposite is La Niña, when the seawater on the west coast of South America is cooler than usual, leading to droughts in some areas and more hurricanes in the Caribbean.

Read more about extreme weather

Learn about greenhouse gases with my greenhouse gas candy models.

Summer 2024 was the hottest on record!

Extreme weather and climate change.

Take a look at my climate change resources for kids.

The post What is Extreme Weather? appeared first on Science Experiments for Kids.

Have you ever wondered how a sea is different to an ocean? The two are often used interchangeably, but they have many differences.

Differences between an ocean and a sea

Oceans are bigger than seas. They cover 70% of the planet and have an average depth of 3800m.

Oceans are not contained by land. Seas are fully or partially enclosed.

Oceans are generally deeper than seas.

Ocean currents affect the climate around the world.

How many oceans are there?

There are five oceans — the Pacific, Atlantic, Southern, Indian and Arctic. Although the oceans are split into five distinct areas, they are not split by land and are one huge body of water.

Examples of seas

Mediterranean Sea

Caribbean Sea

Black Sea

North Sea

The post What's the difference between a sea and an ocean? appeared first on Science Experiments for Kids.

The Earth rotates once on its axis every 24 hours. As it rotates, the sun shines on different parts of it. When the sun shines on one side of the Earth, it's daytime and nighttime on the opposite side.

What are time zones?

The Earth is divided into 24 time zones. Everyone in each zone sets their clocks to the same time, and some countries have multiple time zones. Time zones were created to standardise time in a specific region.

How many time zones are there?

The Earth has 24 time zones.

What is the time difference between time zones?

Each time zone differs by one hour.

Why do we have time zones?

Time zones help us coordinate time around the world. Without time zones 5 pm in one part of the world would be a very different part of the day to 5 pm somewhere else, so things would become very confusing.

What are lines of longitude?

The Earth is a sphere shape. Lines of longitude ( or meridians ) are imaginary lines of equal length drawn from the North Pole to the South Pole.

The Prime Meridian runs through Greenwich, England, and has a longitude of 0 degrees. The antimeridian on the opposite side of the Earth has a longitude of 180 degrees.

What is Greenwich Mean Time?

Greenwich Mean Time ( GMT ) is the point of reference for global time zones. In 1972, GMT was replaced by Coordinated Universal Time ( UTC ) for global timekeeping.

UTC is more accurate than GMT as it corrects for the fact that the duration of the day isn't constant through the year due to the rotation of the Earth on its axis. UTC uses measurements of the Earth's rotation and readings from atomic clocks around the world.

What happens if a country spans multiple time zones?

Large countries like the United States, Russia and Canada have multiple time zones. The USA and Canada have 6 time zones, and Russia has 11.

Where is the first place to celebrate New Year?

Kiribati, in the Pacific Ocean, is the first place to welcome the New Year.

Where is the last place to celebrate New Year?

The islands of Niue and American Samoa are the last inhabited places to celebrate New Year.

The post What are Time Zones? appeared first on Science Experiments for Kids.

The deepest part of the ocean is in the Challenger Deep valley of the Mariana Trench, which is about 10,935 metres deep ( almost 11km )! This is deeper than Mount Everest is tall.

The Mariana Trench is in the Western Pacific Ocean. The deepest section is named after the two ships that first explored it, HMS Challenger and HMS Challenger II.

Trenches form when tectonic plates collide, forcing the edges downwards. The Mariana Trench formed when the Pacific Plate was subducted under the Mariana Plate.

What lives in the Mariana Trench

The depths of the Marinara Trench are dark and cold ( although there are very hot hydrothermal vents, too ), pressure is intense, and food is in short supply.

Some remarkable animals have adapted to survive in these extreme conditions. The Barreleye fish has a transparent head containing eyes that point upwards so it can see its prey.

The SeaDevil Anglerfish is small but has sharp teeth and a glowing light protruding from its head. The Osedax ( Zombie ) worm secretes acids to reach the bones of its food and then uses bacteria to convert the bone into food!

Mariana Trench Challenge

Read more about the mysterious marine animals that live in the depths of the Mariana Trench, and then design your own! Will your animal create its own light? Will it be transparent, gelatinous, wormlike, or have other special features that will help it survive in the extreme deep of the ocean?

Fun Facts about the Ocean

The Earth has five oceans: the Pacific Ocean, Atlantic Ocean, Indian Ocean, Southern Ocean, and Arctic Ocean.

About 70% of the Earth's surface is covered by oceans.

The longest mountain range is underwater! The Mid-Oceanic Ridge is over 56,000km long.

The Pacific Ocean is home to the Ring of Fire. A group of active volcanoes.

Animals that live in the ocean have adapted to survive in salt water.

The Pacific Ocean is the biggest ocean.

Phytoplankton and algae in oceans create around half of the oxygen we breathe.

The Great Barrier Reef is the largest coral reef in the world.

The Atlantic Ocean is the saltiest ocean.

The Great Pacific Garbage Patch is an area of litter and debris that has become trapped by ocean currents. Much of the rubbish is plastic, as it isn't biodegradable and is so commonly used. The sun breaks down plastic into very small pieces, a process called photodegradation. These tiny bits of plastic enter the food chain and, if enough at the surface, block sunlight, affecting the marine life below the surface.

The post How deep is the ocean? appeared first on Science Experiments for Kids.

Have you ever wondered why balls bounce? This activity uses differently shaped balls to investigate how and why balls bounce differently.

I've included FREE instructions for a science investigation to find the bounciest ball with a handy table for recording results.

Balls to use:

• Rugby ball
• Football
• Tennis Ball
• Ping pong Ball
• Basketball
• Squash ball

Look at the differently shaped balls and try bouncing them on the floor. What do you notice?

Things to think about

Which ball do you think will be the hardest to bounce in the direction you want it to bounce?

Are there any similarities between the balls that bounce the highest? What kind of sport are they used for?

Can you bounce each ball into a container? Are some harder than others? Is this related to the type of game they are usually used for?

Why do balls bounce science investigation

This simple science experiment investigates how the shape and size of a ball affects how far and for how long it bounces.

You'll need
Pen and paper
Different types of balls
Tape measure
Chalk

Instructions
Look at the different types of balls and try bouncing them gently on the floor.

Place the balls in order from most bouncy to least bouncy.

Use a long ruler or tape measure and chalk to mark heights of 0.25m, 0.5m, 0.75m, 1m, 1.25m, 1.5m and 1.75m on a wall outdoors.

Drop the balls gently one by one and record the height of the first bounce. Try to use the same force each time and drop each ball from the same height.

Record the number of bounces each ball makes before stopping.

Repeat 3 times for each ball and calculate the average height reached and number of bounces.

More investigation ideas

Try dropping the ball without extra force and then applying force to find out when it bounces higher.

Observe which balls jump straight upwards and which bounce off at an angle.

Remember - when comparing how different balls bounce, consider the conditions you should keep the same, such as the height from which the ball is dropped and the force used to drop it.

Why do balls bounce?

When a ball is dropped, gravity pulls it toward the ground, slowing it down so that each bounce is shorter and shorter until, eventually, the ball stops bouncing.

The force of the ball hitting the hard ground puts an equal force back onto the ball, meaning it bounces back up. This happens because balls are made from an elastic material, allowing them to be squashed or stretched and then return to their original shape. If the ball was made of a softer material, like plasticine, it would be squashed on the ground and wouldn't bounce back up, or if it were made of a hard material, such as glass, it would break when dropped.

Why do balls stop bouncing?

When a ball is held in the air, it has potential energy ( this is the energy stored in the ball because of its height ). When the ball is dropped, gravity pulls it down, and the potential energy is converted into kinetic energy. When the ball hits the ground, some energy is lost in the collision, and so the ball loses energy each time it bounces until there's no energy left.

Remember - energy is always conserved; the total energy is not lost, but changes form.

Extension ideas

Try bouncing your balls on different surfaces to investigate how changing the surface, changes the bounce.

More Sporty Science for Kids

Test your reaction time using just a ruler! This is great fun to do with a friend to find out who has the fastest reaction time. You can also investigate to find out if your reaction time can be improved.

Try one of my 20 easy sports science investigations for kids! These include finding out how much sugar certain drinks contain, how to keep bones strong and healthy and even making a model lung!

Try this fun investigation into skipping rope lengths from Science Buddies.

We've also got lots more exciting science experiments to try. I'd love you to take a look around!

Don't forget to tag me on social media if you try any of our easy science experiments for kids. We loved seeing them in action!

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Universal Time or Coordinated Universal Time ( UTC ) is the world's reference point for time. It's like a huge, extremely accurate clock for everyone, no matter where they are on Earth.

Universal Time was once based on Greenwich Mean Time, which is based on the Earth's rotation, but that has changed to precise atomic clocks, which are much more accurate.

UTC doesn't observe Daylight Saving Time and is 1 hour behind the UK.

See the current Coordinated Universal Time.

The post What is Universal Time? appeared first on Science Experiments for Kids.

Freshwater freezes at 0°C. The presence of salt lowers the freezing point, and the higher the salt content in the water, the lower the freezing point gets.

This is why salt is often used to grit icy roads in winter. It slows down water freezing on roads, making driving safer.

Seawater contains salt. It will freeze, but it requires lower temperatures than freshwater. Usually, only very cold parts of the sea, such as the Arctic and Antarctic, are cold enough for sea water to freeze.

Seawater freezes at around -1.8°C.

Why is seawater salty?

Salt in seawater is mostly caused by mineral ions washing into the water. Carbon dioxide in the air dissolves into rain, making it acidic. The acidic rain lands on rocks and starts to erode them, releasing mineral salts ( including sodium and chloride ) into the sea. Sodium Chloride is the chemical name for the salt we eat!

The Dead Sea is an example of a body of water that has become very salty. It's so salty that visitors can sit on the surface!

Did you know?

Blocks of frozen seawater are known as floes.

Humans cannot drink salt water.

When seawater freezes, the salt molecules are pushed below the surface of the ice. This means polar ice is actually freshwater!

Does salty water freeze science investigation

You can find out if salty water freezes in your kitchen! This simple hands-on science activity takes just a couple of hours and only requires a few basic supplies.

You'll need

Two small, empty plastic bottles or small bowls

Water

Salt

Freezer

Instructions

Place the same amount of water into each bottle.

Add two tablespoons of salt to one bottle and label this salt water.

Label the second bottle, plain water.

Place both bottles in a freezer and check them every 30 minutes.

You should find the salty water freezes more slowly than the plain water.

Does salty water freeze? Investigation Template

My handy experiment template guides you through the investigation with easy-to-follow instructions and space for results.

More science experiments using salt

Use salt to lift a piece of ice with string. In this clever trick, the salt melts the ice around the string. The ice then refreezes over the string, allowing the ice cube to be lifted.

Find out how to cool a drink with ice and salt.

Make a salt lava lamp. This is a fun twist on the more traditional lava lamp.

The post Does salty water freeze? Science Investigation appeared first on Science Experiments for Kids.

The Moon doesn't make its own light. We see it because light from the Sun reflects off the lunar surface, but why does the Moon look white?

If you could actually stand on the Moon, it would look mostly grey with areas of brown and yellow, depending on the minerals present.

The Moon appears white for several reasons.

The surface of the Moon is coated in a layer of dust, which consists mostly of grey basalt. This layer of dust is called regolith.

The regolith reflects light from the Sun without favouring any particular wavelengths. This means our brains process the light we see reflected as white.

Changing colours of the Moon

You might have noticed that as well as appearing white, sometimes the Moon looks yellow, orange or even blue.

Of course, the moon is always the same colour, but it appears to look different to us on Earth as lightwaves from the Sun reflect from the Moon down to Earth. Particles in the Earth's atmosphere can cause the lightwaves to scatter, changing the moon's appearance. Pollution in the air and the moon's position can also make it appear different colours.

Yellow or Orange Moon

The moon appears yellow or orange when it's close to the horizon. This means the light reflecting from the moon has to travel through more atmosphere than usual. The short wavelength colours scatter, but we see the longer wavelength colours such as yellow and orange.

A yellow/orange moon is sometimes called a Harvest Moon, as in the days before outdoor lighting, the light from the big harvest moon allowed farmers to work for longer once the sun went down.

Blue Moon

A blue moon is rare, hence the saying 'once in a blue moon'. Blue moons occur when the atmosphere is dusty, such as after a volcanic eruption. The red wavelengths of light are scattered, making the Moon appear blue.

Red moon

Red moons are known as blood moons. This colour change happens during a total lunar eclipse when the Earth blocks most of the sun's light. The light that does manage to reach the moon has to pass through the Earth's atmosphere first. The shorter wavelengths of light are scattered, so only longer wavelengths are left to reflect back to us.

More about the Moon

Find out how craters form on the moon with a simple science activity using marbles.

Learn about the phases of the Moon with oreos!

Build a model of a lunar eclipse.

The post Why does the Moon look white? appeared first on Science Experiments for Kids.

Hiccups occur when the diaphragm starts to spasm. No one really knows why they happen, but they're thought to happen when the diaphragm gets irritated or stimulated.

The diaphragm is a thin layer of muscle that separates the chest cavity from the abdomen. When it spasms and tightens, it makes you breathe in air too quickly. The air is stopped when the glottis ( opening between the vocal cords ) closes suddenly, which is what makes the hiccup sound.

Hiccups are usually temporary and more annoying than anything else, but persistent hiccups should be investigated by a medical professional.

Causes of hiccups

Anything that irritates the diaphragm or stretches the stomach can cause hiccups.

Common causes of hiccups are:

Eating or drinking too quickly. This leads to swallowing air, which can irritate the diaphragm.

Eating spicy or hot foods.

Fizzy drinks.

Sudden temperature changes.

Swallowing air.

Feeling nervous or excited.

How does the diaphragm work?

When you breathe in, the diaphragm moves down to help pull air into the lungs. When you breathe out, it relaxes to help air move out of the lungs. If the diaphragm becomes irritated and moves less smoothly, you get hiccups.

How do you get rid of hiccups?

There are lots of different ideas for how to get rid of hiccups. Do any of these work for you?

• Hold your breath and count to 10.
• Drink a teaspoon of vinegar.
• Get someone to make you jump.
• Slowly drink ice-cold water.

How do you get rid of your hiccups?

The post What causes hiccups? appeared first on Science Experiments for Kids.

Ultra-processed foods are food products that are heavily processed before reaching supermarket shelves. These types of foods usually contain lots of chemicals such as preservatives, sweeteners, food colouring and emulsifiers. Generally, the more a product has been altered from its original form, the more likely it is to be ultra-processed

Ultra-processed foods are usually of low nutritional quality with high levels of sugar and salt. The benefit of ultra processed foods is that they typically taste good and have a long shelf life, but if eaten in excess can contribute to health issues.

It's tough to completely avoid ultra-processed foods, and some are worse than others. For example, processed wholegrain bread has more nutritional value a fizzy drink. The key is having a balanced diet with lots of fruits, vegetables, lean meat, nuts and seeds.

Examples of ultra-processed foods

Ready meals

Ice cream

Fast food items

Processed meats - sausages, hot dogs

Some breakfast cereals

Crisps, biscuits

Sugary drinks

Examples of unprocessed foods

Fruit, vegetables, milk, eggs, meat, seeds and nuts that have no added ingredients.

Examples of processed foods

These are foods that could be made at home, such as jam, homemade bread, cheese and tinned fruit.

How can to tell if a food item is ultra-processed

Check the ingredients

Ultra-processed foods usually have a long list of ingredients, including additives, preservatives, artificial colours, flavours and sweeteners. These are generally foods you couldn't make at home.

Check for heavily refined ingredients such as oils, flours and sugars.

Look at the nutritional value

Ultra-processed foods often have high levels of sugar, salt and unhealthy fats.

Find out more

Buy a selection of foods, or search the ingredients online and create a table of processed and unprocessed foods. One idea is to choose a food type, such as bread, and try to find five ultra-processed and five less-processed types.

Discover how ultra processed food may affect the brain with this article from the BBC.

Watch The Science Behind Food That Isn't Food.

The post What are ultra-processed foods? appeared first on Science Experiments for Kids.

The Milky Way is an unfathomable 13 BILLION years old! It started to form about 800 million years after the Big Bang.

The Milky Way is home to planet Earth, up to 100 billion planets, and around 200 billion stars!

The Earth is located in the Goldilocks Zone of our solar system, meaning it's far enough away from the sun not to be too hot, but close enough that the Earth isn't completely frozen. Luckily for us, the Earth is also in a prime position in the Milky Way for life to survive. Orion's arm is about 25000 light years from the centre, keeping us away from dangerous radiation levels and exploding supernovas.

Facts about the Milky Way

The Milky Way is a spiral galaxy.

A galaxy is a massive collection of stars, dust, gas and dark matter held together by gravity.

The Milky Way is about 100,000 light-years across.

At the centre of the Milky Way is a supermassive black hole called Sagittarius A*. Luckily for us, our solar system is about 27,000 light-years away.

One of the biggest stars in the Milky Way is a hypergiant star called VY Canis Majoris. It's thought to be around 250000 times more luminous than our Sun.

Earth is located in the inner rim of the Orion arm of the Milky Way.

The next closest large spiral galaxy to Earth is the Andromeda galaxy.

Don't forget to take a look at my other Big Science Questions!

The post How old is the Milky Way? appeared first on Science Experiments for Kids.

Diamond is the hardest natural substance on Earth.

Why is diamond so strong?

Diamond is made up of a network of carbon atoms that each form four strong covalent bonds. The strong bonds take a lot of energy to break, so diamond has a high melting and boiling point.

This type of structure is called a giant covalent structure, as all the carbon atoms are bonded to each other by strong covalent bonds.

The strong covalent bonds also hold the atoms in a rigid lattice structure, which makes diamond very hard.

Uses of diamond

In cutting tools

Jewellery

Diamond does not conduct electricity as there are no free electrons.

Learn more about diamonds over on Live Science.

The post What is the hardest natural substance on Earth? appeared first on Science Experiments for Kids.

Robins are a bird we commonly associate with winter and Christmas, but why do robins have red breasts? The red colour looks amazing next to white snow, but it also makes the bird a target for predators.

Why do robins have a red breast?

There are several reasons why robins have a red breast:

Male robins with a brighter red breast are thought to be more attractive to female robins.

Older robins have a bigger red area. This is thought to serve as a warning to younger robins to stay off their patch. Robins are a very territorial bird.

The post Why do robins have a red breast? appeared first on Science Experiments for Kids.

The northern lights have fascinated humans for centuries. The incredible natural light display has been associated with many legends and tales over the years, but the phenomenon is actually caused by the interaction between charged particles from the sun, the Earth's magnetic field and atmospheric gases.

The northern lights appear when tiny electrically charged particles from solar winds collide and excite atoms of gases in the Earth's atmosphere. The atoms emit the coloured light we call the northern lights.

Auroras are mostly seen near the poles of the Earth, where the magnetic field isn't as good at deflecting the charged particles from the solar winds.

What is an aurora?

An aurora is a natural display of coloured light.

Where do auroras occur?

Auroras mostly occur near the poles of the Earth. In the northern hemisphere, the northern lights are called aurora borealis. In the southern hemisphere, the southern lights are called aurora australis.

Where can you see the northern lights?

The northern lights can generally be seen across northern Canada, Alaska, Greenland, Scandinavia, and Russia.

Where can you see the southern lights?

The southern lights are more difficult to see as they mostly occur over Antarctica.

Why are the northern lights coloured?

The colours of the northern lights depend on the gas particles that are involved in the collision with particles from the solar wind. Red and green colours are from excited oxygen atoms, and pink and blue are from nitrogen atoms.

Magnetic Fields and the Aurora

The Earth's magnetic field is created by the movement of molten iron and nickel in the outer core. The magnetic field is strongest near the poles. The Earth acts like a giant magnet.

You can learn more about magnets with my easy magnet science experiments.

The post What are the Northern Lights? appeared first on Science Experiments for Kids.

The horizontal, rectangular shape of a sheep's pupil gives them a wide field of vision and superior depth perception. This allows them to see any potential predators easily and navigate uneven ground. Sheep can see almost everything around them without needing to turn their head.

The rectangular shape also allows sheep to narrow the pupil to a very thin slit, regulating the amount of sunlight entering the eye. This is an advantage when grazing in open areas.

Rectangular pupils are an adaptation that allows sheep to thrive in their environment.

Which other animals have rectangular pupils?

Goats

Cats have vertical rectangular pupils.

Don't forget to check out our other science question and answer pages.

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Fireworks are often used to celebrate special events or times of the year. In the UK, Fireworks are most commonly used around Bonfire Night on November 5th.

There's a lot of interesting science in fireworks. They have to be propelled high into the air, burst the outer casing at the correct altitude and then create the colourful explosions and noises people like to see.

Most fireworks consist of an outer shell in a tube-like shape made from paper or plastic. The casing holds the different chemicals needed to create the firework effect.

Fireworks are launched by lighting a fuse underneath, which ignites a lift charge. The charge creates hot gases that propel the fireworks into the air.

When the firework reaches the desired height, the shell bursts open, and the firework effect is seen. Each colourful spark or star in a firework is created by small explosive pellets of various chemical compounds, which produce a bright, colourful effect when ignited.

The colours of a firework depend on which metal salts are used.

Commonly, strontium produces a red colour, barium a green colour, copper a blue colour and sodium a yellow colour.

Did you know the word firework comes from the Greek word pyrotechnics?

When were fireworks invented?

Humans have been using fireworks since around 200 BC. Although fireworks back then were very different to the ones we use today. The Smithsonian website has a great overview of the fascinating history of fireworks.

Remember, fireworks are dangerous and should only be used by trained professionals.

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Most spiders have eight eyes. Some species have less, but they always have an even number! Despite having so many eyes, the majority of spiders still can't see very well and rely on their sense of touch and smell to navigate around their environment.

Spider Facts

Insects have large compound eyes ( with multiple lenses ), but spiders have simple single-lens eyes.

Spiders produce silk using their spinnerets.

Most spiders are carnivores and eat insects.

Spiders moult ( shed their exoskeleton ) instead of growing continuously.

Arachnids only have two body parts: a cephalothorax and an abdomen.

In some species, female spiders eat the male after mating.

Spiders are arachnids, not insects.

Different types of spiders make different types of web.

Spiders are found on every continent except Antarctica.

Some species of spider look like ants, which helps them avoid predators.

If you compare by weight, spider web silk is stronger than steel.

Spiders have four pairs of legs.

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Have you ever wondered why the clocks go back? It's always nice to get a lie in when the clocks turn backwards, but not so good when they go the other way.

Daylight Saving Time was first used in the UK in 1916. It basically borrows an hour of light from the morning and moves it to the evening, so the light isn't wasted while people sleep. It's also thought to save energy, as people are less likely to use heating and lighting when there is natural light outdoors.

Clocks fall back in fall and spring forward in spring!

History of Daylight Saving Time

In 1907, William Willett, a British builder, wrote about the waste of daylight and campaigned to get Britain to change the clocks, but he sadly died of flu before DST was established.

In 1961, the German Army turned the clocks forward to conserve energy, and many European governments followed suit.

When do the clocks go back in 2024?

In the UK, the clocks go back by one hour at 2 am on the 27th of October. The time always moves back by one hour on the last Sunday in October and then forward on the last Sunday in March.

What is Daylight Saving Time?

Daylight Saving Time ( DST ) is the time in the summer months between the end of March and the end of October.

In the UK, Daylight Saving Time is known as British Summer Time ( BST ).

Do all countries use Daylight Saving time?

Not all regions observe DST, and the start and end dates can also vary.

Related activities

Read about the summer solstice.

Make a simple sundial.

References

https://en.wikipedia.org/wiki/William_Willett

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To answer this question, you first need to understand how sound travels on Earth. In very basic terms, sound travels from the source of the sound to our ears by vibrating air molecules. Sound waves need a medium to travel through. Space is a mostly empty vacuum, so there's no medium for sounds to travel through. In summary, no, you can't hear sound in space like we can on Earth.

However, scientists use a process called sonification to convert the different waves found in space into sounds.

Listen to the sounds of space

This data sonification of the black hole at the centre of the Perseus Cluster is amazing!

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The pH scale measures how acidic or alkaline a solution is. It ranges between 0 and 14.

Acids have a pH of less than 7.

Alkalis ( or bases ) have a pH of over 7.

pH 7 is neutral.

How is pH measured?

pH is measured using an indicator. An indicator is a dye that changes colour in the presence of an acid or alkali.

Commonly used indicators used to determine pH

• Universal indicator
• Litmus
• Methyl orange
• Phenolphthalein

The image below shows the pH chart for Universal Indicator.

Universal Indicator is a mixture of other indicators.

I have a blank version of the image above available for students to use to fill in the example boxes.

Who created the pH scale?

The pH scale was created by a Danish biochemist named Soren Sorensen in 1909.

Simple science experiments for learning about pH

A very basic pH indicator can be made using the liquid left over from boiling red cabbage in water.

The indicator is a purple colour but turns red in the presence of an acid and green if an alkali is added.

A basic indicator can also be made from the leaves of a poinsettia plant!

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Hot air balloons work thanks to convection currents. The heat source under the balloon heats the air inside. A convection current inside the balloon keeps the air warm as heated air continually rises, cools and falls to be heated again.

The warm air inside the balloon is less dense than the cooler air on the outside, making the air balloon rise upwards.

Launching a hot air balloon in warm weather is much harder than in cool weather, as the air inside the balloon has to be heated more on a hot day to make it less dense than the external air. If temperatures get too high, the lining of the balloon can be damaged.

The image below shows the convection current inside the balloon heating the air.

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Brownian Motion is the random movement of particles suspended in a liquid or gas. The movement is caused by particles colliding with each other.

Brownian Motion is named after a botanist, Robert Brown, who noticed pollen grains moving around randomly in water under a microscope. Even though pollen grains are much larger than water molecules, there were still enough collisions for them to be moved.

Robert Brown didn't understand why the pollen grains he observed were moving, but he was the first scientist to document this kind of movement. It was Albert Einstein who explained that water molecules were moving the pollen grains, and Brownian Motion was used as evidence for the kinetic theory of matter.

This video explains Brownian Motion brilliantly!

What's the difference between Brownian Motion and Diffusion?

• Diffusion is the movement of particles from a high to a low concentration. The particles have a direction of travel. In Brownian Motion, the movement of particles is random.

• Diffusion occurs when there is a concentration gradient. Brownian Motion occurs due to the movement of other particles in the liquid or gas.

Science concepts

Diffusion

Brownian Motion

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The Earth started to form around 4.6 billion years ago! It's thought that a star far away in space exploded, causing huge amounts of interstellar dust to collapse in on itself. Our Sun formed first, and then the rest of the planets.

The Earth formed from rock and dust being pulled together. The heat from the core caused tectonic plates to move and crash into each other, causing volcanoes and earthquakes.

The first oceans are thought to have formed around 4.3 billion years.

When did the first life form on Earth?

It's thought that bacteria emerged around 3.5 billion years ago.

The first humans didn't appear until around 2 million years ago, although they were quite different to modern-day humans.

Find out more about the Earth and our Solar System

This article from Smithsonian is a brilliant overview of the history of life on Earth.

Make a model of the Earth's layers showing the inner core, outer core, mantle and crust.

Read about the big bang theory and find out how the universe is expanding!

More Science Questions

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Freezing point depression occurs when a substance lowers the freezing point of another substance. One example is adding salt to water. A solution of salt and water has a lower freezing point than water alone.

Melting and freezing: a recap

Melting is when a solid turns into a liquid. The temperature at which a solid melts is called the melting point.

Freezing is when a liquid turns into a solid. This is called the freezing point and is generally the same as the melting point for the same substance.

Freezing and melting are both reversible processes.

Freezing point depression demonstrations

1. Make a frosty tin can

If you place a mixture of salt, water and ice inside a tin can, frost will appear on the outside! We made a frosty snowman with ours.

2. Cool a drink - FAST!

Place a bottle or can in a bowl of water, ice and salt, and you'll find the temperature of the water drops very quickly, with the added bonus of cooling down the drink inside.

Find out how to cool a drink quickly!

3. Make ice cream in a bag using ice and salt

Make ice cream in a bag using the freezing power of ice and salt.

4. Adding salt to roads in winter

Grit ( salt, gravel and stone ) is often sprayed on roads in winter to stop cars from skidding. When snow falls on a road with grit applied, it mixes with the salt, lowering the snow’s freezing point which stops ice from forming. A fun way to demonstrate this is an investigation to find out whether salty water freezes.

If you're curious about space, the human body and nature don't forget to take a look at my other science questions and answers!

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A magnet is an object that produces an invisible magnetic field. A magnetic field is an area where magnetic materials experience a force.

Objects attracted to a magnet are either a magnet themselves or are made from a magnetic material.

The magnetic force in a magnet flows from the north to the south pole, which creates the magnetic field.

Magnet facts for kids

Magnets have invisible magnetic fields.

Compasses contain a tiny magnet.

Only iron, steel, nickel and cobalt are magnetic.

Magnets can also be made from neodymium and samarium ( rare earth metals )

The north pole of one magnet repels the north pole of another magnet. Like poles repel.

North and South poles are attracted to each other.

Did you know Earth is like a giant bar magnet thanks to its iron core? That's why the Earth has a North and South Pole.

You can make a compass with a magnet.

Uses of magnets

To separate different materials in a recycling plant

Toys

Compass

MRI machines

Clasps in Jewellery

What is an electromagnet?

An electromagnet forms when current through a wire causes a magnetic field around the wire.

The long coil of wire is called a solenoid. The magnetic field of a solenoid is the same as that of a bar magnet.

How can you increase the strength of an electromagnet?

There are three ways to increase the strength of an electromagnet.

1. Increase the current going through the wire
2. Add more turns of wire to the solenoid.
3. Use a soft iron core. Iron is used as it doesn't stay magnetised when the current is turned off.

Uses of electromagnets

Bells

Headphones

Induction hobs

MRI machines

Learn more about magnets with my easy magnet experiments for kids!

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The Coriolis Effect refers to how the objects moving on the surface of the Earth appear to follow a curved path due to the rotation of the Earth. It is named after Gaspard Gustave de Coriolis who first described the effect.

The Coriolis Effect influences the movement of wind.

Wind is moving air caused by differences in air pressure. Energy from the sun warms air above land and sea. Warm air is less dense than cold air so it rises creating an area of low pressure. Cooler air moves to where the warm air has risen from creating wind!

Air tries to move from an area of high pressure to an area of low pressure.

Wind mostly blows from one direction on Earth. Warm air rises near the Equator and flows towards the Poles where it cools, sinks and flows back to the Equator. HOWEVER, most winds don't flow directly from north to south as they are also bent by the rotation of the Earth. This bending is caused by the CORIOLIS EFFECT!

Learn more about wind with my wind experiments and activities!

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You may have seen my post about Dreamachine's amazing brains activities a few days ago. Dreamachine is a wonderful new resource all about the wonders of the brain! The resources include hands on science activities, more than 30 easy to follow lesson plans and even teacher CPD focussed on wellbeing. They are great for both home and school and we have really enjoyed trying them out.

As well as the primary lesson plans and activities geared towards families there is a fantastic digital tool called Life's Big Questions hosted by the brilliant Martin Dougan from CBBC's Newsround.

There are five interactive challenges, each exploring how we experience the world around us through our senses, inviting children across the UK to share what's important to them in the world.  The big questions delve further into the incredible potential of the human brain and are a wonderful addition to the other Dreamachine activities.

The Big Questions would be great for a whole school or class assembly or as an introduction or finale to a brain, perception or senses topic.

I don't want to spoil it for you, but the big questions are guaranteed to make you think, wonder, ask more questions and even laugh!

We especially liked how you can see at the end how other people have answered some of the questions! We loved taking part and can't wait to see the answer to the final BIG QUESTION!

This post was created in collaboration with Dreamachine

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The question 'How old is the universe?' has intrigued astronomers for centuries. The discovery of leftover light from the big bang was not only supporting evidence for the big bang theory but also allowed scientists to calculate the age of the universe. The big bang is the current accepted theory of how the universe began and the start of time as we know it.

After the big bang the universe expanded very quickly. As it expanded it cooled. Remember energy cannot be created or destroyed, so all the energy in the universe today was around at the time of the big bang!

As the universe expanded the energy became stretched out over a bigger area and so the universe cooled and became less bright.

The first atoms formed about 380,000 years after the big bang when electrons and protons joined together. Photons ( another really small particle ) cooled and stretched to form cosmic microwave background radiation or CMB radiation. It is this radiation that scientists measure to learn about the beginning of the universe.

By estimating how far light from CMB radiation has travelled to reach Earth, the age of the universe can be calculated.

Scientists agree that the Universe is about 13.8 BILLION YEARS OLD.

Learn more about the universe

Learn more about the universe with Chromoscope. Chromoscope lets you explore the Universe in a range of wavelengths!

Help scientists search for new worlds by joining The Backyard Worlds: Planet 9 citizen science project.

Make a simple model of how the universe is expanding.

Science Concepts

• The Big Bang
• Atoms and subatomic particles
• Electromagnetic radiation

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The Big Bang is a theory about how the Universe began. Most scientists believe the Big Bang theory which is the current accepted model for the beginning of the Universe.

Georges Lemaître first proposed the big bang theory in 1927. The theory was supported by Edwin Hubble's research into cosmological red shift in 1929.

What is the Universe?

The Universe is basically everything that exists, it is phenomenally large and always expanding.

What is the Big Bang theory?

The Big Bang was a massive expansion ( not an explosion ) from a single point. It was the start of time and the Universe has been expanding ever since.

It's hard to understand but forces, time, matter, energy and every physical thing in the Universe expanded out of that single point.

The Big Bang - a summary

• All the matter in the Universe occupied a very dense, very hot and very small space.
• A sudden expansion occurred and the Universe as we know it started to form.
• Around 13.8 BILLION years later the Universe exists as we know it!

Despite its explosive beginning the Universe as we know it today took a VERY long time to form. Our solar system wasn't created till around 9 BILLION years after the Big Bang! To put this into context the Universe is thought to be around 13.7 billion years old.

Is there any evidence for The Big Bang Theory?

There most definitely is!

Evidence for the Big Bang Theory

Red Shift

Scientists have noticed an increase in the wavelength of light ( shifted towards the red end of the visible light spectrum ) coming from far away galaxies. Measurements of red shift show that far away galaxies in all directions are moving away from us.

Galaxies further away have greater red shift than those closer which shows that far away galaxies are moving away faster.

If galaxies are moving away from us that means they were once closer!

Cosmic Microwave Background Radiation

Cosmic Microwave Background Radiation ( CMBR ) is low frequency electromagnetic radiation that can be detected in all directions throughout the universe. It is though this is the leftover energy of the Big Bang!

Are there any other theories for how the Universe started?

Steady State Theory

The Steady State theory states that the Universe has always existed as it does today and as it expands new matter is created. There's no beginning or end, just a constant state of expanding universe and new matter that keeps the density of the Universe about the same.

What will happen if the Universe keeps expanding?

No one knows...but there are a few theories.

The Big Chill

In this scenario galaxies will become so far apart they run out of gas to make new stars. Existing stars would slowly run out of power and the Universe would become cold and dark.

The Big Crunch

In this theory the Universe expands and then starts to pull back together. Eventually the whole Universe would collapse into one very dense point.

The Big Rip

The Big Rip is a theory where space expands and expands until eventually everything is ripped apart.

We may not know how or if the Universe will end, but we do know that it's not going happen for billions of years!

Science Concepts

• Space
• Matter
• Energy
• The Big Bang

More reading

Read an interesting debate about a Universe with no beginning.

Could there be a multiverse?

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The summer solstice is the longest day of the year when the Earth's North Pole is tilted closest to the sun. There are two solstices each year. One in June and one in December. The time of the solstice is the same all over the planet, but the season depends on where on Earth you are ( Northern or Southern Hemisphere ).

The term solstice is made up of the Latin sol meaning the sun, and sistere which means make stand still.

In the Northern Hemisphere the June solstice is the first day of summer and the December solstice the first day of Winter. In the Southern Hemisphere it's the other way round.

Why are the days longer in summer?

There are more hours of daylight in summer because of how the Earth revolves around the sun.

In the Northern Hemisphere ( the half of the world above the equator ), the longest day is the 20th or 21st of June.

The opposite happens in the Southern Hemisphere, where the longest day is the shortest day in the Northern Hemisphere.

This is because the Earth is tilted. The half of the Earth tilted towards the sun is in summer, and that part of the Earth tilted away from the sun is in winter. You can see in the image below that each hemisphere of the Earth is tilted towards the sun for one-half of the year and away from the sun for the other half of the year.

What is the longest day of the year?

The longest day of the year in the Northern Hemisphere is the 20-22nd June.

When is the shortest day of the year?

The shortest day of the year in the Northern Hemisphere is the 20th-23rd December.

Why does the exact date of the Summer Solstice change?

This is because of leap years which cause the date to change a little each year.

What is an Equinox?

The equinox is the day of the year when the tilt of the Earth is 0, and there are equal hours of day and night. This happens twice a year, on the first day of Spring and the first day of Autumn. Equinox means equal.

Summer Solstice Activities for Kids

These easy ideas are super simple and should help children understand the science behind the summer solstice.

Why do we have night and day?

This simple demonstration I wrote for Lets Lasso the Moon many years ago is a great practical demonstration as to why we have night and day.

How does the Earth orbit the sun?

This very simple, hands-on demonstration shows how the Earth orbits the sun and the moon orbits the Earth.

Visit Stonehenge

Stonehenge needs an article to itself, as the history behind it is incredible. At each solstice, the rising sun reaches the middle of the stones, but if you happen to be passing by, it really is an amazing sight to see regardless of the time of year.

Make a rainbow

Did you know sunlight ( white light ) is actually made up of a spectrum of 7 different colours? You can see these when a rainbow forms. Another way to show the spectrum of colours in white light is to make a rainbow using a prism.

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If you’ve ever visited a beach on a hot day you may have found it to be windier by the sea than it is inland. Sea breezes are caused by convection currents.

What is a sea breeze?

Sea breezes occur on summer days because land heats up faster than the sea.

Warm air rises as it is less dense than cooler air. As the warm air rises, cooler air from over the ocean moves over land to take its place. It is this movement of warm and cool air that creates a sea breeze!

The opposite happens at night when the surface of land cools faster than the surface of water. The warmer air over the ocean rises and cooler land air flows out to sea to replace it.

Learn more about the weather with my collection of weather science experiments!

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If you've ever blown a dandelion that's gone to seed, you've probably found that the little parachute-like seeds detach easily and seem quite delicate. However, dandelion seed puff balls are stronger than you think!

A whole dandelion head can be placed in water and removed again, almost completely undamaged!

What happens to a dandelion in water?

Each dandelion seed is attached to a tiny parachute like structure ( called a pappus ) made up of lots of filaments which allow the seed to fly away on the wind. This clever dispersal method clearly works well as dandelions are very abundant.

Is a dandelion waterproof?

The pappus is omniphilic, which means it repels both oil and water. When the tiny hairs of the pappus are submerged in water, they close up, trapping a water droplet inside.

This feature may help dandelions survive in wet conditions.

Dandelion Facts

A special air bubble forms on top of the filaments above the seed to help keep it in the air longer.

The word dandelion means lion's tooth.

Dandelion seeds are produced asexually, so they don't need to be pollinated. This means all dandelions are genetically identical to their parent plant.

Dandelion flowers close up at night.

All parts of the dandelion are edible!

Although they don't need to be pollinated, dandelions are a very popular source of food for pollinating insects such as bees, moths, and butterflies. Their long flowering season makes them especially useful to insects. Next time you do some weeding, think about leaving some dandelions behind!

How does a dandelion clock form?

When the flower reaches a certain age, it starts to dry out, making the petals fall off, which exposes the seed ball. When the wind blows, the seeds are carried away from the parent plant. This is called seed dispersal.

More about seed dispersal

Learn more about seed dispersal methods by making a sticky seed or an exploding seed pod.

This video explains the science of dandelion seed and how it is specially adapted to travel far from the parent plant.

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How many times a day do you yawn? Do you find yourself yawning if someone near you yawns? Do you associate yawning with boredom or tiredness or both?

Humans yawn around 7-10 times a day, although I have already yawned 3 times writing this so perhaps if you think about yawning you yawn more...

Yawning is associated with being tired or waking up. No one really knows why we yawn but it's thought to be linked with regulating brain and body temperature.

Opening the jaw causes an increase in blood flow to the mouth area which is then cooled as extra air rushes in.

Another theory is that yawning allows for a quick increase in oxygen when carbon dioxide has built up.

Why do we yawn when other people yawn?

Again, no one really knows, but it's thought to be linked with empathy. If they need to yawn maybe you do too?

Or it could be a form of social mirroring, just like you smile back at someone when they smile!

Do animals yawn

All vertebrate animals yawn!

This article from National Geographic about a study into lions yawning is really interesting with some great information on why yawning is contagious!

Facts about yawning

The study of yawning is called chasmology!

Some penguins yawn to attract a mate!

Yawning in animals can be a warning signal.

Babies yawn before they are born!

Some studies have shown a relationship between brain size and length of a yawn!

Activities for learning about yawning

Start a diary and record how often you yawn each day. Each time you yawn try to count how long it lasts and the cause.

Yawn around your friends, do they copy you?

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Hedy Lamarr and George Antheil

Hedy Lamarr (1914-2000 ) and George Antheil (1900 - 1959 ) invented a system which allowed radio waves to jump onto different frequencies. The idea was originally to stop the US Navy's radio signals from being jammed by their enemy in World War 2.

Hedy's invention of radio frequency jumping technology was a vital step in the development of Wi-Fi. Although Hedy Lamarr and George Antheil successfully received a patent for their frequency hopping idea in 1942, it wasn't recognised until many years later when an updated version was used during the Cuban Missile Crisis in 1962.

Hedy Lamarr was not only a scientist but also a famous Hollywood actress in the 1930s and 1940s. She didn't invent Wi-Fi but did work on a concept that ultimately led to Wi-Fi.

Vic Hayes

Vic Hayes is often called the Father of Wi-Fi. He was the head of the committee that introduced the international standard for wireless networking in 1997.

Dr John O'Sullivan

Dr John O'Sullivan led a team of scientists in Australia who worked on groundbreaking technology to reduce the echo of radiowaves. This led to the development of the wireless LAN.

You can see how it's difficult to name a single inventor of Wi-Fi as its development was built on ideas and inventions from multiple people.

What does Wi-Fi stand for?

Some people think Wi-Fi stands for Wireless Fidelity, but it actually doesn't stand for anything!

What is Wi-Fi?

Wi-Fi is a wireless networking technology that allows wireless devices such as laptops and mobile phones to access the internet. It's also known as WLAN which is short for wireless local area network.

Most people use a small wireless router to connect to the internet.

What radio frequencies are used for Wi-Fi?

Currently, radio frequencies of 2.4 gigahertz and 5 gigahertz are used.

If you want to learn more about the history of Wi-Fi the National Museum of Australia has a great overview.

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What do you picture when you think of an engineer? Do you imagine someone wearing a hard hat putting various mechanical pieces together? Or someone sat at a desk all day? Do you picture a man? Engineering is so much more than just mechanics, definitely not a desk job and certainly not just for men, although there are currently many more male engineers than female.

Engineering is all about solving problems with science and maths to make life better.

It was engineers who created the first tools, the first irrigation systems, the first engines, vehicles and many, many more inventions that make our life better every single day. Engineering has been around for 1000s of years and is a huge part of human history. Steam engines powered the industrial revolution, the invention of the wheel revolutionised transport and it is engineers who will play a vital part in working through our climate crisis. Today, we need engineers more than ever before!

Types of Engineering

There are lots of different fields of engineering encompassing everything from microscopic nanobots to the biggest industrial installations.

The below are just some of the different types of engineering. You can see that there's a huge variety of options and endless possibilities for all types of engineer.

Civil Engineering

Civil engineers design, construct and maintain buildings and other structures such as roads, bridges and dams. This type of project usually benefits people, improving life for the general public.

Mechanical Engineering

Mechanical engineering is the design and maintenance of machinery including vehicles, machines used in industry and tools.

Biomedical Engineering

Biomedical engineers work to improve healthcare. This could be working on things like MRI scanners, creating prosthetic limbs, or even creating robots to operate or deliver medicine.

One very exciting field of biomedical engineering is tissue engineering which involves creating tissues in the lab to replace parts of the body. Imagine if we could grow whole new organs for people!

Chemical Engineering

Chemical engineers work with materials and chemicals to create useful products. Chemicals engineers will be vitally important in the future as they try to find sustainable alternatives to plastics and help create efficient renewable energy sources.

Electrical engineering

Electrical engineers work with electricity create new and inventive products. These can include everything from the smallest microchips to large industrial systems.

Computer Engineering

Computer engineers design computer systems, networks, software and hardware.

Environmental Engineering

Environmental engineers work to monitor, reduce and prevent pollution. They are also involved in cleaning up polluted areas.

Engineering through the ages

The Wheel

Who invented the wheel?

The oldest wheel to be discovered was a potters wheel in Mesopotamia from around 3500BC. It's not known who invented the first wheel, but this simple invention changed the world!

Stonehenge

Stonehenge is an astonishing piece of engineering dating back to around 3100BC. It seems practically impossible that Stonehenge was built thousands of years before cranes, or any kind of power. No one knows how the huge stones were transported, but it is thought they were lifted upright using wooden frames and ropes. Construction of Stonehenge took 1500 years!

Pyramids of Giza

The Pyramids of Giza were built as tombs for the Pharaohs of Egypt around 2500BC. These monumentally impressive structures are an incredible feat of engineering and construction. No one really knows how they were built!

Aqueducts

Aqueducts use gravity to move water from a source to final destination. Roman aqueducts used tunnels and bridges as part of the transportation system.

The first aqueduct in Rome is thought to have been built around 310BC.

Archimedes Screw

The Archimedes Screw is a device invented around 250BC used for moving water upwards. Confusingly the Archimedes Screw was not necessarily invented by Archimedes, but is a useful device that is still used today.

You can make your own Archimedes Screw using some plastic piping and a tube.

The Great Wall of China

The Great Wall of China is another incredible feat of engineering, and the longest ever piece of human construction. The oldest parts date back to around 206BC but construction continued right up to the 17th Century. The Great Wall is one of the new 7 Wonders of the World, a Unesco World Heritage Site and the longest artificial structure in the world!

The Thames Tunnel

The Thames Tunnel was the first tunnel to be built under water in the world and is still in use today! The tunnel opened in 1843 and was first used for pedestrians before being converted for use by trains. The tunnel was designed by Marc Isambard Brunel who created a device called the tunnelling shield to help with construction. More modern versions of this device are still used now.

Marc Brunel was helped by his son Isambard Kingdom Brunel with the project. Isambard later became chief engineer of the Great Western Railway which stretches from London to Bristol and Exeter. Isambard Kingdom Brunel is also famous for the Clifton Suspension Bridge in Bristol which at the time it opened ( 1864 ) was the longest bridge in the world.

Trans-Siberian Railway

The Trans-Siberian railway is the worlds longest railway connecting Moscow to Vladivostock ( 5772 miles ). The railway line travels through forests, mountains and rivers which gave engineers involved in its construction many challenges to overcome. Additionally, Siberia is very, very cold so engineers had to consider the effect of melting and freezing permafrost on the track.

Hoover Dam

The Hoover Dam was built in the 1930s to provide hydroelectric power, prevent flooding and give the people of Las Vegas a reliable water supply to help with the irrigation of crops. It's 200m thick at the bottom and 14 m thick at the top!

Hoover Dam straddles the Black Canyon of the Colorado River to create the US's largest reservoir, Lake Mead. The dam is a gigantic concrete curve which holds back water while transmitting the pressure into the walls of the canyon.

Water released from the reservoir drives turbines to generate electricity!

In Vitro Fertilisation

You might think IVF is biology, not engineering but biomedical engineering is a fast growing field using engineering for medical purposes.

IVF was developed in the 1960s and 70s with the first IVF baby being born in 1978!

The Channel Tunnel - 1994

The Channel Tunnel is another feat of engineering and is the world's longest, continuous undersea railway tunnel. It connects England to Northern France and is used for passengers and vehicles.

Construction took five years and the tunnel is one of the 7 Wonders of the Modern World.

International Space Station

The first module of the International Space Station was launched into space in 1998. The ISS is not only a massive engineering achievement but an impressive collaboration between sixteen nations! The space station was assembled in space sometimes by robotic arms and sometimes by humans. It is a true engineering masterpiece!

Did you know the space station orbits the Earth 16 times each day and is about as long as a football pitch?

Hong Kong-Zhuhai-Macau Bridge

The Hong Kong-Zhuhai-Macau Bridge ( opened in 2018 ) connects Hong Kong to China and is the world's longest sea bridge. This engineering superstructure also contains an underground tunnel ( allowing ships to pass through ) and three artificial islands!

The bridge has been specially designed to withstand extreme weather and natural events such as typhoons and earthquakes!

More Human Feats of Engineering

Panama Canal

The Panama Canal was built at the start of the 20th Century to connect the Atlantic and Pacific Oceans for trade and travel purposes. Engineers had to consider differences in water levels, tricky terrain including lakes and mountains and landslides.

Bailong Elevator

The Bailong Elevator opened in 2002 and is the world's tallest outdoor elevator. It's not for those with a fear of heights as it reaches 326m high giving an incredible view over the Wuling Mountains in China.

Itaipu Dam

Itaipu Dam, located on the Brazil-Paraguay border is one of the world's largest hydroelectric power stations. The dam produces enough electricity to cover a large percentage of Paraguay's needs.

How to get kids excited about engineering?

Engineering is all about designing, inventing and testing, so hands-on creative STEM projects are a great place to begin.

My easy engineering projects are fun, challenging and use equipment you probably already have. Learn about strong shapes with paper columns or egg shells, test different edible foundations in an earthquake and lots more!

The James Dyson website also has some simple challenges to get you started.

The post What is Engineering? appeared first on Science Experiments for Kids.

The biggest animal that lives in the sea is the blue whale. Blue whales can grow to 30 metres long, weigh up to 200 tonnes and have a heart the size of a small car!

The blue whale is also the biggest animal on the planet and the largest animal that has ever lived!

Are blue whales dangerous?

Blue whales are not dangerous to humans, they have no teeth and are not aggressive

How big is a baby blue whale?

A baby blue whale weighs around 4000 kg at birth and can be 8 metres long! Baby blue whales gain around 90kg of weight a day, that's a lot of eating!!

How do blue whales eat?

Blue whales eat by filtering huge amounts of water to get krill. They eat the krill and expel the water.

How many of you could swim alongside a blue whale?

Measure how tall you are and then work out how many of you could swim alongside a blue whale!

What is a group of blue whales called?

A group of blue whales is called a pod!

Make a whale food chain

Blue whales are at the top of their food chain with no natural predators, although they are sometimes attacked by Orcas.

How long do blue whales live?

Blue whales can live for up to 90 years!

The post What is the biggest animal in the sea? appeared first on Science Experiments for Kids.

You might think butterflies' brightly coloured wings make them stand out to other animals, but the colours are often a defence mechanism to deter predators!

The coloured leaves of butterflies are an adaptation that has evolved over millions of years.

Why are butterflies brightly coloured?

A warning

Bright colours act as a warning to other animals that the butterfly doesn't taste nice or is poisonous.

For protection

Some species are coloured for camouflage, making it hard for predators to spot them. The Indian leaf butterfly has wings that look like leaves.

Some also have eyespots to make other animals think they are bigger than they are.

The owl butterfly has a large eye spot, making the wings look like the face of an owl!

To attract a mate

Butterflies also use their bright colours to attract a mate.

What about caterpillars?

Butterfly larvae are called caterpillars. Like butterflies, some blend into their environment and don't move around much during the day; some are hairy, which makes them unattractive to predators, and some are brightly coloured, which warns predators that they are toxic.

Butterfly Facts

Butterflies and moths have sensors ( called chemoreceptors ) on their feet, allowing them to taste their food.

They have compound eyes.

Butterflies are the only insects that have scaly wings.

The patterns on the wings of a butterfly are symmetrical.

Butterflies have an interesting lifecycle and undergo a process called metamorphosis, where they transform from caterpillars to butterflies.

Butterflies are important pollinators. They transfer pollen between plants as they feed on nectar.

During the chrysalis or pupae stage of its lifecycle, a butterfly is very vulnerable to predators as they can't move or defend themselves. The chrysalis often looks like a leaf or twig, which gives it a little protection.

Butterflies, like all insects, have an exoskeleton.

You can find butterflies all over the world, except Antarctica.

Butterflies are cold blooded, which means they cannot regulate their own body temperature. They are much more active in warm, humid weather than when it's cold. If you've ever visited a zoo with a butterfly house, you probably noticed how warm it was.

Camouflage activities for kids

Place different colours of small sections of string on grass. Which are easiest to see?

Use different materials to create a camouflage outfit for a small soft toy. Try placing it in different areas outdoors to find out where the camouflage works the best.

Fun ideas for learning about butterflies

Do you know what the biggest butterfly in the world is called?

Create an edible butterfly life cycle with my FREE printable activity sheet!

This butterfly identification sheet from the Wildlife Trusts is brilliant!

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Hooke's law states that the amount of force applied to an elastic object is proportional to how far it stretches.

However, if the object is overstretched it will not spring back.

Hooke's Law only applies if an elastic object is not overstretched.

Objects are made from lots of molecules with bonds between them, if too much force is applied the bonds break meaning the object will not return to its original shape.

Hooke's Law applies to elastic objects, but they don't stretch forever. When an object will no longer return to its original size we say it has reached its elastic limit.

How to investigate Hooke's Law

One way to investigate Hooke's Law is to add increasing masses to a spring and measure how far the spring stretches ( extends ) until it will no longer return back to its original length.

You should find that the extension of the spring is proportional to the force added.

F = force

k = spring constant

x = length of extension or compression

Deformation is when a force changes the shape of an object either by stretching or compressing it. Different materials respond differently to forces.

Who was Robert Hooke?

Robert Hooke was a brilliant English polymath who discovered the law of elasticity which we now know as Hooke's Law.

Hooke also invested the compound microscope which he used to look at all types of objects revealing a tiny world of micro-organisms that people hadn't seen before. He published a book called Micrographia containing drawings of his findings which included a flea and a head louse. He is also thought to be the first person to use the word 'cell'.

Robert Hooke was born in 1635 and died in 1703. He worked with Robert Boyle and helped form the Royal Society. Hooke is also famous for his clashes with Isaac Newton.

More science for kids

Have a go at one of my many science investigations for learning about forces.

Try this simple stretchy material investigation for learning about elastic limit.

The post What is Hooke's Law? appeared first on Science Experiments for Kids.

Sublimation is when a solid becomes a gas without turning into a liquid first.

There are three states of matter. Adding or removing energy from a substance can change the state it is in. For example water is a solid below 0^oC ( freezing point ), a liquid above 0^oC ( melting point ) and a gas above 100^oC ( boiling point ).

Boiling, melting and freezing point temperatures are different for different substances.

What is an example of sublimation?

One example of sublimation is when dry ice ( solid carbon dioxide ) turns from ice to carbon dioxide gas when it comes into contact with air.

The opposite of sublimation is deposition.

What is an example of deposition?

An example of deposition is when frost forms from water vapour on cold ground or a window pane on a cold day.

These changes are known as physical changes as they can be reversed by heating or cooling. The final substance is the same matter as before the physical change. The opposite of a physical change is a chemical change which cannot easily be reversed. The final substance is not made of the same matter as before the change.

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Moonbows ( lunar rainbows ) form in the same way as rainbows, but the light source is the moon rather than directly from the sun.

The moon is lit mostly by light from the sun, but also by light from other stars and light reflected from Earth.

Rainbows and moonbows form when light is refracted through water droplets splitting it into the colours of the rainbow.

Moonbows are much fainter than rainbows, as moonlight is much less bright than sunlight. This makes them very difficult to see with the human eye.

Moonbows are most likely to be seen when the moon is full and the sky is extremely dark. Full moons occur every 29.5 days.

More about the Moon

Earthquakes can occur on the moon and are known as moonquakes.

Do you know why the moon looks different throughout a month?

Full moons have nicknames that were once used to track the time of year. Read more about moon nicknames with the Farmers Almanac!

Discover how the Earth, Sun and Moon orbit each other with a fun activity!

A blue moon is when we see more than one full moon in a month!

Read our fun facts about the moon.

The post What is a Moonbow? appeared first on Science Experiments for Kids.

Where does rain come from? Most rain comes from the sea! Water on land, in lakes and seawater evaporates when it's heated by the sun to form a gas called water vapour.

Water vapour rises and cools back into water droplets forming clouds. When the droplets of water are big enough they fall as rain which eventually flows back to the sea.

This process is called the water cycle. Water on earth is recycled over and over.

Rain Science Activities

Measure rainfall with a DIY rain gauge.

Red Ted Art has a brilliant cloud spotter for learning about different types of clouds.

Learn about the water cycle with my easy water cycle printable sheet.

Find out what shape a raindrop really is.

Learn about cloud names and shapes with the Met Office.

Make a lovely eggy cloud breakfast with these egg white cloud shapes.

Affiliate links

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Chemistry is the study of matter. Matter is basically anything that occupies space and has mass!

We use chemistry everyday and everywhere. When you bake a cake the ingredients are chosen, measured and then cooked so they react together to create something tasty (or not, depending on how you combine ingredients and cook them ).

The way food rots is chemistry, the way your soap foams up when mixed with water is chemistry and the way cleaning products clean is chemistry!

All the interactions that happen in our environment are chemistry too from the way pollutants from cars spread through the air to cleaning up oil spills in the sea.

There are lots of different types or branches of chemistry including:

Organic Chemistry - the study of substances that contain carbon.

Inorganic Chemistry - the study of compounds that don't contain carbon.

Biochemistry - the study of chemical processes inside living cells.

Nuclear Chemistry - the study of reactions that occur inside atoms.

Great Chemistry Experiments for Kids

Try one of my classic chemistry experiments such as building and launching rockets, erupting a volcano, writing with invisible ink.

Find out why the Statue of Liberty is green!

Make your own pH indicator and test strips with red cabbage water!

Chemistry resources from around the web

Stay up to date with all things related to chemistry with the RSC.

The post What is Chemistry? appeared first on Science Experiments for Kids.

Batteries are used to power toys, torches and other items that need energy to work.

Batteries store energy as chemical energy which is converted into electrical energy when the battery is part of a circuit.

When a battery is placed inside a circuit it pushes charge around the circuit. This pushing force is called voltage.

Batteries contain two different types of metal and an electrolyte.

Batteries contain three things:

• A positive electrode
• A negative electrode
• An electrolyte - a liquid or paste

Both electrodes have an end ( terminal ) that extends out of the battery.

Make a lemon battery

You can make a very simple battery with a lemon, copper wire or coin and a zinc ( galvanised ) nail. The lemon juice, copper and zinc react with each other creating electricity!

Electrons build up on the zinc nail and leave the copper coin or wire. The electrons want to move to the copper coin but can't travel through the electrolyte. When a wire is connected between the nail and coin electrons flow down the wire between the nail and copper coin. If an LED is placed in the circuit it will light up as current passes through ( current is electrons flowing through the wire ).

What's in a dry battery?

Real batteries aren't made with lemons but have a metal cap which acts as the positive electrode attached to a carbon rod and a negative electrode made from zinc. The electrolyte is mixed with manganese dioxide making it solid. This type of battery is called a dry battery or cell.

A battery that is only used once is a primary battery, this is the type of battery is commonly used in remote controls and other small items. Batteries that can be recharged are secondary batteries ( examples of these are mobile phones and car batteries ).

Remember

Electric current is the flow of electrons around a circuit. If the circuit breaks the current cannot flow.

More circuit investigation ideas

Create a circuit with graphite!

Make a potato battery!

Find out what happens when you break a circuit by adding a switch.

The post How do batteries work? appeared first on Science Experiments for Kids.

Voltage is the force that pushes current around a circuit. Imagine a battery being like a pump, pushing the current around the circuit. A more complicated way of defining it is that voltage is the difference in electrical energy between two points on a circuit.

You can buy batteries with different voltages or use multiple batteries to increase the voltage in a circuit. The bigger the voltage the more current flows around a circuit.

How is voltage measured?

Voltage is measured in volts.

The voltage of a standard AA battery is 1.5V.

The voltage of household wiring varies around the world but is 230V in the UK and 120V in the US.

When we made a potato battery we used a voltmeter to check the voltage.

What is current?

Current is the flow of charge ( negative electrons ) around a complete circuit. If the circuit breaks the current stops flowing. Current is measured in Amperes!

You can learn more about electricity and circuits with one of my easy electricity projects.

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An element is a substance that cannot be broken down into another substance. Each element is made up of its own type of atom!

The periodic table lists elements in order of atomic number and is laid out so elements with similar chemical properties form columns ( groups ).

Atomic number is the number of protons in the nucleus of the atom. The number of protons for each element is equal to the number of electrons.

Columns are called groups, and rows are called periods.

Remember - stuff about elements and atoms

Atoms are REALLY, really small!

All atoms in an element are identical.

All elements are different.

Most elements are solids at room temperature, but some are liquid, and some are gases.

Atoms are the building blocks of all materials.

Every element has a name and a symbol, but remember, the symbol might not be obvious. ( Li - lithium, K - Potassium, Na - Sodium )

Some elements are very common, and some are extremely rare.

Activity ideas for learning about elements

If you want to learn more about elements, this interactive periodic table from the Royal Society of Chemistry is brilliant! You can also get it as an app.

Make some edible molecules. A molecule is two or more joined together.

The post What is an element? appeared first on Science Experiments for Kids.

Atoms are not all the same. They have different numbers of electrons, protons and neutrons.

Each different kind of atom makes up an element.

An atom consists of a positively charged nucleus surrounded by negatively charged electrons which move around the nucleus in orbits. Much of an atom is empty space!

Electrons are negatively charged.

Protons are positively charged.

Neutrons have no charge.

Atoms have an overall neutral charge as the number of electrons is equal to the number of protons.

If an atom loses an electron, it becomes a positive ion. It has more protons than electrons.

If an atom gains an electron, it becomes a negative ion. It has more electrons than protons.

How big is an atom?

This video explains just how small atoms are brilliantly!

Atoms and Molecules

Atoms can join together to form a molecule.

For example, a molecule of oxygen gas consists of two oxygen atoms joined together. One fun way to learn about molecules and atoms is to make candy molecule models!

How many atoms make up a human?

An adult human is thought to contain around 7 Octillion atoms!!

What is atomic number?

Atoms of the same element have the same number of protons. The number of protons is the atomic number of the element.

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How do we see things? We see things because of light!

The simple explanation

Light bounces off objects and enters our eyes allowing us to see them.

It's harder to see at night as there's less light to bounce off objects.

Let's make it a bit more complex

Light enters the eye through the cornea ( the bit on the front of the eye ). The pupil controls the amount of light entering the eye. If you look in the mirror on a sunny day you'll notice your pupil is small, but it becomes bigger when there's less light allowing more to enter the eye.

As the eye is curved it bends the light entering it and so an upside down image is created on the retina which the brain very cleverly turns the right way up.

Muscles around the lens allow it to slightly shape allowing the eye to focus light on the retina.

What are sources of light?

The sun, light bulbs and fire are sources of light.

Facts about light

Light travels in straight lines.

Light can pass through transparent ( see through ) materials but not opaque materials.

Shadows form because light cannot pass through the object casting the shadow.

Light takes about 8 minutes and 20 seconds to travel from the Sun to the Earth.

Light can be natural or human made.

We can see the moon because it reflects light from the sun!

Visible light is made up of lots of all the colours of the rainbow. A prism can be used to split white light into its constituent colours.

Did you know there are different types of light? Gamma rays, microwaves and the rest of the electromagnetic spectrum are all types of light.

Rainbows form because water droplets split light into the colours of the rainbow.

Thomas Edison invented the lightbulb.

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A variable is a factor in an experiment that can be changed.

When you set up an experiment in the correct way you need to think about control, independent and dependent variables.

What is an independent variable?

The independent variable is the factor changed in an experiment. There is usually only one independent variable as otherwise it's hard to know which variable has caused the change.

What is a dependent variable?

The dependent variable is the variable measured in an experiment. It depends on the independent variable!

What is a control variable?

Control variables are variables that must be kept the same in an experiment.

Usually only one variable is measured and an experiment investigates how changing the independent variable affects the dependent variable.

Experiment ideas for learning about setting up a fair test

Investigating the effect of exercise on heart rate

If you wanted to investigate the effect of exercise on heart rate the variables would be as follows

Control variables

Same person exercising

Same method used to measure heart rate.

Independent variable

Type of exercise or no exercise.

Dependent variable

Heart rate

Investigating the effect of viscosity of a liquid on flow rate

If you wanted to investigate how the thickness of a liquid affects it's flow rate the variables would be as follows.

Control variables

Gradient of ramp

Distance travelled by each liquid

Amount of each liquid used

Independent variable

Liquid used

Dependent variable

Time taken for each liquid to travel a set distance

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Fossils are the preserved remains of animals and plants that lived a long time ago.

Fossils can also be evidence of a prehistoric animal or plant, such as footprints or evidence of nests or burrows. These are called trace fossils.

Not all remains become fossilised. Fossilisation is actually quite rare. Most animal and plant remains decompose after they die ( or are eaten by scavengers), but if the remains are covered by sediment ( usually sand, mud or lava ), they may become fossils.

Stages of fossilisation

1. The soft parts of the animal decompose, leaving the hard skeleton behind.
2. Layers of sediment build up on top of the skeleton. As more and more layers build up, the pressure on the lower layers increases, and they start to turn into sedimentary rock.
3. The animal skeleton dissolves as water passes through it. This leaves a gap in the layers of rock the same shape as the skeleton.
4. Minerals from the water fill the gap left by the skeleton to form a replica of the original bone.

Quick Fossil Facts

Most fossils are of marine animals, as the seabed is the ideal place for layers of sediment to build up over a dead animal.

It takes thousands and sometimes millions of years for a fossil to form.

Fossils are forced up to the surface when tectonic plates collide, when ice sheets melt or can be pushed up as new rock forms beneath them.

The Latin word fossilis means dug up.

Fossilised animal poo is called coprolite and is very useful as it gives clues to what animals ate.

Weathering and erosion of layers of rock also allow fossils to be found.

Dinosaur fossils have been found on every continent.

Fossils have been found at the top of Mount Everest. This is because the Himalayas were formed when two tectonic plates collided, forcing heavier rock down and lighter rock upwards, making the top of the mountain home to 400 million year old fossils that were once at the bottom of the ocean!

A mould fossil is a 3D impression of an organism that has decomposed in sediment, leaving an imprint behind.

A cast fossil is when the mould becomes filled with organic material forming a replica of the original bone.

Animals can also be fossilised if they become trapped in amber, tar or ice!

Fossil Activity Ideas

Make a super simple fossil with clay. This is an example of a mould fossil.

Make a fossil of a Coelacanth.

Find out about the pioneering fossil hunter Mary Anning and make a model ammonite.

This gummy fossil activity from Teach Beside Me is fantastic too!

Finally, have a go at making your own mould fossil.

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Single use plastics are plastic items that are designed to be used just once. Things like food packaging, straws and water bottles are all single use items. Around half the plastic thrown away is single use, although hopefully, this percentage is dropping as the use of reusable drinking bottles and straws becomes more common

Did you know it can take up to 400 years for plastics to break down? Even as they are breaking down, plastics don't just disappear. Animals can get trapped and tangled up in them or mistake them for food and try to eat them. Even biodegradable plastics can take 100s of years to break down completely.

Plastic has even been found in the Mariana Trench. The Mariana Trench is the deepest point on Earth, so this is VERY bad news.

When small pieces of plastic are eaten by fish and other animals, they build up in the fish, which are then eaten by humans, potentially causing all kinds of health problems.

Plastics from clothes

Did you know that clothes made from polyester, nylon, acrylic and other man-made materials often contain plastic? When you wash them, tiny microfibres of plastic come off the clothes and can eventually end up in the sea, where they make their way into the food chain.

This process of toxins and chemicals from plastic building up in animal tissue is called bio-accumulation.

More about pollution and plastics

Kids Against Plastic has some great resources for teaching kids about the effects of plastic and pollution.

Learn more about pollution with my ideas for teaching kids about pollution.

Take the plastic pledge to find out how you can save the planet from plastic!

Activity ideas for learning about plastic

Design a device to fit in a washing machine to catch pesky plastic microfibres.

Create a device for trapping plastic in the ocean. This could be some kind of net, perhaps self-propelled to move around the surface of the sea.

Build new useful products from single-use plastic items. Perhaps turn a water bottle into a plant pot or watering can, use old food packaging as storage for stationary or other items or create a piece of art!

The post What are single use plastics? appeared first on Science Experiments for Kids.

Choose a question to investigate with the Science Sparks Squad. Each week we'll add a new science question and associated activity to help you find the answer!

This idea is that you print off a question you're interested in and then try the activity to find the answer!

Each science experiment or investigation is designed to be easy to carry out using materials you probably already have around the house!

Who are the Science Sparks Squad?

Choose an question, print the sheet and start investigating!

Science Questions

Don't forget to keep popping back, as I'll be adding more every week!

Don't forget to check out my other science experiment instruction sheets too!

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The Earth is located in a planetary system we call the solar system located in one of the four spiral arms of the Milky Way galaxy. Our solar system consists of 4 inner planets ( Mercury, Venus, Earth and Mars ) and 4 giant planets (Jupiter, Saturn, Uranus and Neptune ). There are also several dwarf planets ( Pluto, Ceres and Eris are just a few ) around 200 moons, and millions of asteroids and comets.

Light from the Sun takes about 555 days to reach the edge of the Solar System compared to 8.25 minutes to reach the Earth. It's clear we're talking about IMMENSE distances which can be hard to imagine.

Astronomical units can be used to make the distances more manageable.

Working out how far each planet is from the Sun can be tricky as the distance changes depending on where the planet in its orbit. I've used average distances for this activity.

What is an Astronomical Unit?

An astronomical unit ( AU ) is the distance from the Earth to the Sun ( about 93 million miles )

Draw the Solar System

An easy way to draw the Solar System is to scale a drawing to 1AU = 1cm and draw each planet starting from the Sun at 0cm.

Walk the Solar System

To walk the solar system, you'll need to convert the Astronomical Units to something walkable.

If you multiply each distance from the Sun by 100cm, you can easily walk and mark out the Solar System, although you will need a big open space.

For example:

Start with the Sun at 0 cm.

Mercury 40 cm

Venus 70 cm

Earth 100 cm

Mars 150 cm

Neptune 30 metres

Another idea is to use toilet paper and roll out a separate strip for each planet along the ground.

Remember 1 AU is 93 MILLION MILES!!! To put this into context the diameter of the Earth is only 7926 miles!!!

Grab the activity sheet below!

Crazy space facts

Did you know 1.3 MILLION Earths would fit inside the Sun?

1320 Earths would fit inside Jupiter ( if there was no space between them ) which is the biggest planet in the Solar System.

Our solar system is part of a galaxy called the Milky Way!

There is a giant black hole at the centre of the Milky Way that weighs more than a billion Suns!

ELEVEN Earths would fit across the diameter of Jupiter.

Mercury spins so slowly that a year is longer than a day!

Mercury has a very thin atmosphere.

Venus is the hottest planet in the solar system, and its air is so thick that it would crush human visitors in seconds.

Olympus Mons on Mars is three times taller than Mount Everest!

IO ( one of Jupiter's moons ) has over 400 active volcanoes.

Saturn has over 60 moons!

Uranus rolls on its side rather than spinning upright like the other planets.

It would take a plane travelling at normal speed over 570 years to get to Neptune!

Saturn is the second biggest planet, but not very dense. If you could make a bathtub big enough, it would float!

Jupiter has 67 moons ( that we know of ).

If you compare our sun to other stars, it's actually quite small. Hypergiant star VY Canis Majoris is 1400 times wider than the Sun!!!

More space science

Find out more about the wonders of space with one of my easy space themed science experiments!

This video illustrates the size of space brilliantly!

The post How big is the Solar System? appeared first on Science Experiments for Kids.

Shadows are formed when light hits an object it cannot travel through. When you see your shadow on a sunny day, your body has blocked light from the sun. Light travels in a straight line. It cannot bend around your body, so you see a shadow.

Shadows change shape during the day as the sun's position changes in the sky.

In the morning and evening, when the sun is low, shadows are longer than when the sun is high in the sky!

Uses of shadows

Sundials have an arm which forms a shadow. The shadow of the sundial arm changes position as the Earth turns throughout the day. They can be used to tell the time!

Learn about shadows with one of my easy shadow crafts or investigations! You can make shadow puppets, a sundial of your own, a fun shadow frame, draw around shadows and lots more!

The post What is a shadow? appeared first on Science Experiments for Kids.

Are viruses alive is a tricky question that has caused a some debate over the years.

The general view is that viruses are not alive. They don't respire, convert nutrients into energy or excrete waste products like organisms we class as being alive do. Viruses can't even reproduce without taking over another living cell. Once a virus has infected a host cell, it takes over the machinery of the cell to create more virus!

If we compare viruses to a bacteria, bacteria can reproduce independently outside a host, but viruses cannot survive without a host, and usually can't last long on a surface.

4 reasons a virus is not alive

• Viruses don't have cells like other organisms. They have a very basic structure of RNA or RNA ( genetic material ) protected by a simple protein coat.
• Viruses cannot reproduce without a host cell.
• They don't produce their own energy.
• Viruses don't respond to their environment like other organisms.

However, viruses can replicate ( inside a host cell ) and do evolve, so what do you think? Is a virus both living and non-living? The debate is open...

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The Avogadro Constant is used to find the number of particles in a substance.

What is the Avogadro Constant?

The Avogadro Constant is 6.02 x 10²³

What is a mole?

One mole of a substance is the amount of the substance that contains 6.02 x 10²³ particles.

The particles measured can be atoms, molecules, electrons or ions.

National Mole Day is celebrated on the 23rd October each year.

Amadeo Avogadro was an Italian chemist. The RSC has a great overview of his life and achievements that I really recommend you read!

The post What is the Avogadro Constant? appeared first on Science Experiments for Kids.

From the outside a raw egg and a hard boiled egg look the same, so how can you tell the difference?

How can you tell if an egg is raw or hard boiled?

The key is in the spin! A hard boiled egg will spin nicely and a raw egg will wobble.

The raw egg is full of fluid which moves around as it spins making the egg wobble!

If you love eggs, try one of my fun egg experiments!

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Is taste linked to smell? Have you ever wondered why food doesn't taste as good when you have a cold and blocked nose?

When you eat, smell chemicals from the food travel up your nose, where they are detected by tiny nerve endings at the back of the nose. These nerves send a message to the brain, which becomes part of the overall taste sensation you experience.

If your nose is blocked, the food smell chemicals can't reach the nerve receptors, and so the overall taste is not as strong.

The smell of food can also act as a warning. If you open a carton of milk and it smells sour, you know before tasting it that it won't taste good.

Taste and Smell Investigation

One way to investigate how smell affects taste is to close your eyes, hold your nose and ask a friend to feed you something. This activity works really well with different flavour jelly beans as the texture for each jelly bean flavour is the same, but the taste should be different!

Print the activity and try it for yourself!

Find this and more smelly science experiments in Gross Science!

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The scale was initially designed to show the effects of the wind on a battleship at sea.

When is a hurricane warning issued?

Hurricane warnings are issued when winds reach 12 on the Beaufort scale, but this would only be a category 1 hurricane.

Hurricanes are measured on the Saffir-Simpson scale based on their wind speed.

The scale helps estimate the possible damage a hurricane may cause.

Saffir-Simpson Scale

Hurricanes start over tropical oceans as tropical cyclones (intense, rotating storms ) when they reach 74 miles per hour; they are categorised as hurricanes or typhoons in the Northwest Pacific.

Hurricane Katrina was a category 5 hurricane at its peak, with storm surges over 6m high! Over 1 million people lost their homes, and more than 1000 died.

New Orleans suffered the worst flooding, but the hurricane caused damage in Louisiana, Mississippi, Florida, Georgia and Alabama.

Don't forget to check out my other fascinating science questions and answers!

I also have a vast collection of weather activities you might like and lots more wind experiments!

The post What is the Beaufort Scale? appeared first on Science Experiments for Kids.

You might have had an x-ray in hospital if you've hurt a bone or in the dentist when having a check up. X-rays are incredibly useful in medicine and have lots of other uses too.

X-rays are used to view inside objects and materials. If you've been to an airport you've probably had your bag scanned. Airport security use x-rays to help find objects that can't be detected with a metal detector.

Radiographers in hospitals use X-rays to view inside the body to diagnose broken bones. X-rays are transmitted by skin and flesh but absorbed by bones and other dense material.

An x- ray image is created when x-ray radiation is passed through the body onto a detector. Areas where less x-rays pass through ( bones ) are the brighter parts of the image.

An x-ray is an electromagnetic wave. X-rays and Gamma rays are high energy electromagnetic waves which pass through the body with little absoption which is why they are great for viewing inside the body.

X-rays can also be used for inspecting food to look for items that shouldn't be there and for examining fossils!!

X-Ray Activities for Kids

Find out how to keep bones healthy and make your own plaster casts for a doll.

Try this x-ray craft from Homeschool Creations.

Find out about Marie Curie who invented mobile x-ray units which saved 1000s of lives in World War 1.

Don't forget to check out my other science questions for kids!

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Pandas eat it, humans make stuff from it and it's the fastest growing plant on Earth. Bamboo is pretty amazing, but why does bamboo grow so fast?

Did you know bamboo can grow up to 1.2m a day??

Not all bamboo grows at that rate. There are over 1000 different species, adapted to different environments. The fastest growing bamboo is tropical giant bamboo (Dendrocalamus asper).

Why does bamboo grow so fast?

Bamboo grows in dense forests where there's not much light in the lower layers. Plants need light from the sun to grow and survive so must grow tall quickly to reach sunlight.

Unlike most trees bamboo grows with the same diameter so doesn't waste growth thickening it's stalk.

Uses of bamboo

Bamboo has many, many uses and is highly adaptable. Its hollow stems make it very strong. China has bridges made from bamboo and in Japan it is often used for scaffolding as its tensile strength is greater than steel!

Bamboo is also used in medicines, for making clothes, toys and even buildings!

Facts about Bamboo

Did you know bamboo survived closer to ground zero at Hiroshima than any other living thing?

Bamboo is one of the most versatile plants on Earth!

Some bamboo shoots can be eaten.

Bamboo is a great building material as it is relatively cheap, grows quickly, is strong and has great tensile strength.

Don't forget to check out my other science questions kids ask too!

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My children ask questions ALL the time, which I love, but I don't aways know the answer or if I do sometimes it's hard to explain properly to a smaller person. I've pulled together a list of the most common science questions kids ask so you know where to come next time you're a bit stuck for an explanation!

Science Questions for Kids

Questions about Earth and the Environment

What does climate change mean?

Discover what we mean by climate change and find some activities to help learn about it!

Why is the sky blue?

Find out why the sky is blue, and how to make a rainbow!

Why does bamboo grow so fast?

Find out why bamboo grows so fast and why it's so strong!

Animal Questions

Why do dogs lick?

Dogs lick people for many reasons, it can be a sign of affection, attention or enjoyment. They might even just like the taste of whatever they're licking off!

Chemistry Questions

Why do baking soda and vinegar fizz?

I've got many, many ways to demonstrate the baking soda and vinegar reaction. It's a great first chemical reaction to learn about and what we call an acid-base reaction! The vinegar is the acid and the baking soda is the base ( alkali ).

Why does salt melt snow?

Find out why salt melts snow and how it's used in practical applications.

Human Body Questions

What is a scab?

Find out why you get a scab, what they're made from and even how to make one!

What is an x-ray?

Find out about x-rays and their many uses.

Biology Science Questions for kids

What is photosynthesis

Learn about the process of photosynthesis with some easy investigations.

What is respiration?

Learn about respiration with our hands on experiments, some of these are delicious!

Do identical twins have identical fingerprints?

Identical twins often look very similar, but do identical twins have identical fingerprints?

Nature Questions

What is the biggest butterfly in the world?

What is the biggest butterfly in the world? Find out and calculate your own wingspan!

What shape is a raindrop?

What shape is a raindrop? It might not be what you think...

Why does bamboo grow so fast?

Did you know bamboo is immensely strong, grows very quickly and has 100s of uses, but why does it grow so fast?

Why do bubbles pop?

Bubbles form inside a layer of soapy water, but do you know why bubbles pop?

Space Science Questions for Kids

Which is the hottest planet?

Venus is the hottest planet in our Solar System. Venus has a thick atmosphere which traps heat from the Sun but doesn't let it escape.

How long would it take to get to Mars?

It would take about 6 months to get to Mars and another 6 to get home. That's a long time to spend in space!

What are craters?

Find out how craters form with this easy activity using flour and marbles.

How much does the Earth weigh?

It's tricky to calculate but scientists do know how much the earth weighs!

What's inside the Earth?

There are several different layers inside the Earth, on the surface is a thin, rocky crust, under that is the mantle and in the centre a core made from very, very hot liquid metal. As the Earth spins the iron acts like a magnet. This is why a compass needle points the way it does.

Find out what's inside the Earth with this simple play dough model.

Is Pluto a planet?

Pluto was once the ninth planet of out Solar System but was declassified in 2006 and reclassified as a Dwarf Planet. It is located in the Kuiper Belt which is a ring of icy bodies further out than Neptune. Other Dwarf Planets are Eris, Makemake and Haumea.

Are mass and weight the same?

The answer is NO! If you were on the Moon your mass would be the same as on Earth, but your weight would be different! Find out how to work out weight here.

Is Mercury hot or cold?

Mercury is actually both hot and cold! Mercury rotates on its axis very slowly. It takes almost 57 Earth days to rotate. The side facing the Sun is vert, very hot and the side facing away from the sun is very, very cold!

What is a Moonquake?

A Moonquake is an earthquake on the Moon! There are also Marsquakes, Venusqaukes and Sunquakes!

Why do we have day and night?

The Earth spins once on its axis each day. When the Earth is facing the Sun it is daytime and when it spins away from the Sun it is night time. You can demonstrate why we have night and day with a plasticine ball on a stick.

How do astronauts sleep?

Astronauts sleep in sleeping bags attached to the wall of a spacecraft.

What is a Goldilocks Planet?

Just like baby bear's porridge, a Goldilocks zone is where it's not too hot or too cold for life. Earth is a Goldilocks planet.

What is a group of stars called?

A group of stars is called a star cluster! Some star clusters are made up of just a few starts and some have hundreds!

Questions about time

Why do we have leap years?

If you've got any more science questions for kids, leave me a comment and I'll add to the list!

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How much does the Earth weigh? We obviously can't put the Earth on a gigantic scale so it needs a tricky calculation to work it out.

Scientists calculate how strong the gravitational pull on other planets is to calculate weight. Heavier planets have a stronger gravitational pull. We talk about a planets mass rather than weight though as weight is dependent on gravity, so mass is easier to work out!

You would weigh less on the moon than on Earth as there is less gravity on the moon, but your mass would stay the same.

The Earth has a mass of 5,970,000,000,000,000,000,000,000 kg.

Fun Facts About Earth

The Earth is known as a Goldilocks Planet!

It is the third planet from our sun.

Earth's diameter is about 13000km!

Earth isn't really round. Its spin causes the poles to be a bit squashed and the middle to be swollen.

Over 70% of the Earth's surface is water!

Earth Activities

Learn about the Theory of Heliocentrism and Nicholas Copernicus.

Find out what's inside the Earth with this easy play dough model.

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Have you ever wondered what shape a raindrop is or why a drop of water forms a sphere?

Water droplets are spheres because surface tension pulls the molecules into the smallest possible area to give the lowest ratio of surface area to volume. This shape is a sphere.

What shape is a raindrop?

A falling raindrop forms a slightly different shape as drag and air resistance exert pressure on the falling droplet. As the raindrop falls it forms a burger bun type shape with the flat base on the underside. Very different to the image people usually have of a raindrop falling.

Falling raindrops tend to bump into each other and join together. Once they reach a certain size they break apart.

Related posts

Find out how much rain falls where you are with a DIY rain gauge.

Make a rain cloud in a jar using food colouring and shaving foam.

Finally, Inspiration Laboratories has a brilliant cloud in a jar activity!

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The biggest living butterfly in the world is the Queen Alexandra's Birdwing butterfly ( Orinthoptera alexandrae). It's one of the rarest butterflies in the world and is only found in the rainforest of Papua New Guinea.

The wingspan of the female Queen Alexandra birdwing is up to 28 centimetres!

Queen Alexandra's Birdwing butterfly was named by Walter Rothschild and named after Queen Alexandra of Great Britain.

The male and female butterflies differ in size, the colour of their wings and body colour. Females are larger with brown wings and a cream coloured body.

Queen Alexandra's Birdwing butterfly is poisonous to animals who eat it.

Find your wingspan

Queen Alexandra's Birdwing butterfly has a much larger than average wingspan for a butterfly. Can you calculate your wingspan and compare it to that of your friends?

Spread your arms out straight as far as you can.

Ask a friend to measure the distance from the tip of the longest finger on one hand to the tip of the longest finger on the other hand.

That is your wingspan!

You can also try comparing your wingspan to your height, this is known as ape index.

Make a Butterfly Life Cycle

Another lovely butterfly activity is to make a model butterfly life cycle.

All butterflies and moths undergo a process called metamorphosis. Metamorphosis means transformation! There are four stages to butterfly metamorphosis: egg, larva, pupa/chrysalis and butterfly

Another lovely butterfly activity is to watch the process in action with this brilliant butterfly growing kit from Insectlore.

This activity is part of my Around the World in 50 Science Experiment series. Download the passport and try them all!

affiliate links

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Do you know how salt melts snow?

Grit is often sprayed on roads to stop cars from skidding on very cold days. What we call grit is a mixture of salt, gravel and stone.

When snow falls on a road with grit applied, it mixes with the salt, lowering the snow's freezing point and stopping ice from forming.

Water with salt freezes about 5 degrees lower than water without salt.

To be most effective, grit must be dropped onto surfaces before they freeze.

How does salt melt snow - Investigation Ideas

Freeze a solution of salt and water

Try freezing water with salt added and plain water in an ice cube tray. The salty water won't freeze.

Try sprinkling a little salt on the plain water ice cubes. Watch what happens.

Make an icy road

Freeze two sheets of ice. Sprinkle salt and sand on one and leave the other. Watch what happens to the two surfaces.

Try rolling a toy car over both surfaces. The surface without salt should be much slippier than the one with salt.

Melt an ice sculpture

The Artful Parent has a beautiful ice sculpture you can melt with salt, too!

Now you know how salt melts snow!

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A leap year has 366 days instead of the usual 365 days.

We refer to a year as being a leap year when February has an extra day. February 29th is often called a leap day.

Why do we have leap years?

It's all to do with the Julian or Gregorian calendar ( which has 365 days ) and how long it takes the Earth to complete one rotation around the sun.

It takes the Earth 365.24 days ( 365 days, 5 hours, 48 minutes and 46 seconds ) to orbit the Sun, but the Gregorian calendar has only 365 days in a year. If we didn't add a leap days we 'd be around 6 hours short of the New Year each year meaning that our seasons would soon become out of sync with the months.

After 100 years we'd be 24 days out of sync...if that carried on our seasons would be completely switched around in just a few centuries. It would all be very confusing.

What is a leap day?

February 29th is the leap day. It only occurs every 4 years!

How do you know if it's a leap year?

The last two digits must be divisible by 4, although century years are an exception.

Is a leap year every four years?

Leap years are almost every 4 years, but there are some exceptions.

Leap years must be divisible by 4, but if the year is divisible by 100 ( century years ) it must also be divisible by 400. 2000 was a leap year, 1900 was not!

More science of the calendar

Find out what the summer solstice is and make your own sundial!

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Green plants make sugar for growth by a process called photosynthesis. Photosynthesis is a process where light energy is converted to chemical energy in the form of sugars. Photosynthesis provides the main source of oxygen in the atmosphere and is essential for almost all life on Earth.

Photosynthesis made simple

Plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of glucose.

The glucose molecules created by photosynthesis act as fuel for cells and are used for cellular respiration and fermentation.

Photosynthesis Equation

Where does photosynthesis happen?

Photosynthesis takes place in chloroplast cells, which contain a substance called chlorophyll. It is chlorophyll, which gives plants their green colour.

Chloroplasts are one of the organelles in a plant cell. We made a jelly model of plant cell to learn about organelles and plant cell structure.

Sunlight is also needed to make chlorophyll. If plants are kept in the dark, they can't make chlorophyll and will have yellow leaves! You can see this in our multicoloured cress caterpillar.

What affects the rate of photosynthesis

Four factors affect the rate of photosynthesis. The faster it occurs, the more the plant grows.

Light – the more light there is, the faster photosynthesis occurs.

Water – lack of water slows photosynthesis down.

Temperature – photosynthesis works best at around 30 degrees Celsius.

Carbon dioxide levels – photosynthesis is faster if there is more carbon dioxide in the air.

Plants make the energy to grow through a process called respiration. This uses the sugar produced by photosynthesis and oxygen.

How are leaves adapted for photosynthesis?

Leaves are green as they contain lots of chlorophyll, which absorbs sunlight.

They are thin and have a large surface area. This means they can absorb a lot of sunlight, and gases such as oxygen and carbon dioxide can pass in and out of the leaf easily.

Leaves have veins - xylem and phloem, which transport water, minerals and sugars around the plant.

Do only plants photosynthesise?

No!

Plants, algae, and some types of bacteria use photosynthesis to create energy.

A large percentage of the Earth's oxygen comes from phytoplankton in the oceans, which contain chlorophyll and use photosynthesis to create energy.

What is chlorophyll?

Chlorophyll is a green pigment which absorbs energy from blue and red light waves and reflects green light waves, which is why plants look green!

Chlorophyll in a plant is found in an organelle called a chloroplast. This is where photosynthesis occurs.

Why is photosynthesis important?

Photosynthesis also allows plants to make energy for growth and repair, and it has an important ecological impact.

Plants incorporate the carbon from carbon dioxide into organic molecules ( carbon fixation ). This creates a carbon source for animals who cannot create their own and also removes carbon dioxide from the air, slowing down the rate at which it builds up in the atmosphere.

Photosynthesis also creates oxygen, which is needed for most life on Earth!

Do you have more questions? You might find the answers in my collection of science questions for kids.

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A moonquake is the moon equivalent of an earthquake. They tend to be less strong than earthquakes, but last longer.

Apollo astronauts placed seismometers on the Moon between 1969 and 1972, which sent information about the quakes back to Earth. Moonquakes show that the Moon is still geologically active.

Other types of quakes include Marsquakes, Venusquakes and even Sunquakes!

If you're interested in learning about Earthquakes, we've got lots of easy ideas including making your own seismometer!

Moon STEM Activities for Kids

Find out why the Moon looks white.

Bake moon phase cupcakes!

Use my free Moon Log Book to track the phases of the Moon.

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Water and oil do not mix. They are said to be immiscible. This is because water is a polar molecule – its structure means that is has a positive charge one end and a negative charge the other end. Water molecules stick together because the positive end of one water molecule is attracted to the negative end of another.

The structure of an oil molecule is non polar. Its charge is evenly balanced rather than having one positive and one negative end.

This means oil molecules are more attracted to other oil molecules than water molecules, and water molecules are more attracted to each other than oil, so the two never mix.

You can see in the image below how food colouring doesn't mix with oil. The food colouring actually sinks through the oil into the water layer as water is more dense than oil. This is the basis for a firework in a glass experiment.

The two can be forced to mix by adding an emulsifier which creates a mixture of water with oil molecules spread evenly through it or vice versa.

Oil and Water Science Experiments

Use water and oil to demonstrate density. You can make a very simple density jar with just oil and water or use other liquids to make a more complex density column.

Find out what happens if you put a gingerbread man in oil and water.

Try to clean up an oil spill!

Make a lava lamp with oil and water.

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If you've ever made an erupting volcano model you most likely used the baking soda and vinegar reaction to make it erupt. Baking soda and vinegar react to neutralise each other ( vinegar is an acid and baking soda an alkali ) releasing carbon dioxide which is the bubbles of gas you see. If you add a little washing up liquid ( dish soap ) the foam becomes thick, a little like lava!

This reaction is used for lots of fun science experiments including popping bags and blowing up balloons.

Baking Soda and Vinegar Reaction Equation

Baking Soda + Vinegar ----> Carbon Dioxide + Water + Sodium Ion + Acetate Ion

You can read more about the chemistry behind the reaction here.

Try an experiment!

Now you know the science behind the reaction why not try one of our many explosive baking soda and vinegar experiments.

One of our favourites is fizzy colour changing potions! These use red cabbage indicator for the colour changing part and the vinegar and baking soda reaction to make the fizz!

Frozen baking soda ice cubes are great fun too!

More easy science for kids

Don't forget I've got 100s more easy science activities and experiments for kids to try! We've got STEM challenges, kitchen science experiments and lots of ideas for science at home!

If you try any I'd love to see them so please do share on social media and tag @sciencesparks.

The post What is the Baking Soda and Vinegar Reaction? appeared first on Science Experiments for Kids.

What is an emulsion? Two or more liquids that don't mix create an emulsion when one is added to the other. The properties of the new liquid are different to either of the liquids alone. Emulsions are a special type of colloid.

Liquids that don't mix together are called immiscible liquids.

Examples of Immiscible Liquids

Oil and water are examples of immiscible liquids. This density jar shows how some objects float on the water layer and some on the oil layer.

The diagram above shows the difference between a liquid, an emulsion and immiscible liquids.

You can see that in the emulsion, liquid two is spread evenly through the water.

What is an emulsifier?

Emulsifiers are substances which stop liquids in an emulsion from separating. Emulsifier molecules have two different ends. One end is hydrophilic (water-loving) and the other end hydrophobic (water-hating). In the case of oil and water, the hydrophilic end of the emulsifier forms a bond with the water and the the hydrophobic end forms a bond with the oil!

Emulsifiers are used in foods such as ice cream, sauces and biscuits to stop the oil and water from separating!

Examples of emulsifiers

Egg yolks are an example of a food emulsifier. It is egg yolks that stabilise mayonnaise and hollandaise sauce.

Find out more about emulsions with a magic milk experiment. This uses dish soap ( washing up liquid ) as an emulsifier.

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Your skin is a barrier from harmful things in the environment. When skin becomes damaged blood quickly clots ( thanks to platelets in the blood ) around the damaged area to form a dry crust, called a scab. This protects your body from any nasties which could take advantage of the new opening in your skin.

It might feel quite satisfying to pick a scab, but underneath there’s a lot going on and the scab is definitely best left in place. There's dead bacteria, live bacteria, phagocytes ( white blood cells ) and maybe even pus. Pus is yellow gooey stuff which is mostly white blood cells, dead bacteria and skin cells! Macrophages ( a type of white blood cell ) under the scab eat and destroy bacteria. These can call out for extra help from B cells, which produce antibodies to flight infection.

The basic function of a scab is to protect the damaged area while new skin cells are made and any damaged vessels repaired.

If you do manage not to pick them, scabs eventually fall off, revealing the new skin underneath.

Scabs usually start as a red colour which becomes darker as the scab dries and thickens. They often become lighter as the skin heals.

Yellow in a scab is a sign of pus, which is usually a sign of infection and should be investigated by a doctor!

Remember to keep an area of damaged skin, clean and dry.

Try our fake blood recipe to watch pretend blood thicken like a blood clot, then make a jelly scab!

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Respiration is a chemical reaction that is fundamental to all living things. It happens in every cell of every plant and animal.

Respiration is the reaction between glucose (from food) and oxygen in the air you breathe. It produces carbon dioxide and water (waste products) and ENERGY! Energy is needed for movement, growth and repair and generally staying alive.

Glucose + Oxygen --> Carbon Dioxide + Water + ENERGY

Respiration in Animal Cells

Respiration in animal cells occurs in the mitochondria. It is called aerobic respiration, as it uses oxygen. Some microorganisms, such as yeast respire anaerobically ( without oxygen ).

Glucose and oxygen are transported to cells in the blood, and the waste products are removed.

The process can also occur anaerobically if there is a shortage of oxygen. This can happen if you exercise really hard!

Anaerobic Respiration in Animals

glucose --> lactic acid

It's the lactic acid that makes your muscles hurt when you've done a lot of exercise. Lactic acid isn't broken down until you start to respire aerobically again. Anaerobic means 'without oxygen'.

Anaerobic respiration in bacteria creates ethanol as the by-product.

Aerobic respiration produces more energy than anaerobic respiration.

Plant Cells

In plant cells respiration also occurs in the mitochondria of the cell.

Comparison of Photosynthesis and Respiration

You can see from the diagram above that the reactants and products of photosynthesis and respiration are opposites.

Respiration converts nutrients from the soil into energy and happens all the time, but as photosynthesis needs light, it only happens in the daytime.

Photosynthesis converts light energy to glucose which can then be used for respiration. This process allows plants to make their own food!

On a sunny day, photosynthesis occurs faster than respiration, so more oxygen is given off by the plant than is used. This is great for us as we need oxygen to breathe!

Ideas for Respiration Experiments

The gas produced by yeast can be used to blow up a balloon.

Children can see respiration in action by baking bread or pizza dough.

Plant Experiments

Edventures has a super simple activity allowing kids to see bubbles of gas appearing on the leaf of a plant as it photosynthesises.

Find out how plants transport water from the soil to leaves with our capillary action experiment and transpiration investigation.

A hands-on way to learn about plant structure is by dissecting the a flower or plant.

More about cellular respiration

The summary of respiration above is simplified. When we talk about energy in the equation, we mean something called adenosine triphosphate ( ATP ). Respiration turns glucose into ATP via several stages.

1. Each glucose molecule is converted to two pyruvate molecules and ATP.

Anaerobic - no oxygen

If, at this stage, there is no oxygen, anaerobic respiration occurs, and ATP and ethanol ( in bacteria ) or ATP and lactic acid (in animals ) are produced by fermentation.

Aerobic - oxygen present

If oxygen is present after pyruvate is created, aerobic respiration occurs. Pyruvate goes through a process called the Krebs cycle which releases high-energy electrons. This happens in the mitochondria of a cell.

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The Maillard reaction ( often called the browning reaction ) is what's responsible for the browning and aroma of foods as they cook. In very simple terms it is a reaction between amino acids ( building blocks of proteins ) and simple sugars ( reducing sugars ).

It's the Maillard reaction that causes cakes to turn brown. Seared steaks, cookies, biscuits and breads all undergo this reaction.

When egg is used as a glaze, it also acts as a source of protein for the sugar's Maillard reaction. This is why egg is used to give a lovely brown coating to sausage rolls and pastries!

You've probably used the Maillard reaction to get food to look and taste how you want without even knowing what it is. The reaction only occurs in the presence of high heat and the final taste and browning effect depends on the amount of sugar, water, and protein in the food. Caramelisation is another process that occurs at high heat and causes browning, but this reaction is between sugar and water.

Did you know that there was so much chemistry involved in baking and cooking?

Find out more about the science of baking with the Science Sparks Bake Off.

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Weight and Mass can be very confusing and people often use them interchangeably without really thinking about which is correct, but very simply:

Mass is a measure of how much matter an object is made up of. Mass remains constant. The mass of an object on the moon ( or anywhere in the universe ) is the same as on Earth.

The weight of an object depends on gravity. There's less gravity on the moon so the same object weighs less on the moon than it does on Earth.

Mass and Weight Facts

Mass cannot be zero. Everything has mass.

Gravity has no effect on the mass of an object.

Mass is often measured in grams, kilograms and milligrams using ordinary scales.

Your weight depends on where you are in the universe. The stronger the gravitational pull the more you weigh!

Weight is a measure of the force of gravity on an object and is measured in Newtons ( N ). A 1 kg mass has a force of 9.8 N on Earth.

Weight (W) = Mass (M) x Gravitational Acceleration (g)

W = mg

How much would you weigh on Jupiter?

Jupiter's gravitational pull is 2.4 that of Earth, so you would weigh 2.4 times more on Jupiter than on Earth.

How much would you weigh on the Moon?

The gravity on the moon is only 16.5% of that on Earth, so you would weigh a fair bit less on the moon. If you weigh 50 kg on Earth you'd only weigh 8.3 kg on the moon!!

If you think about the astronauts on the International Space Station. Their mass doesn't change much in the journey to the space station, but they weigh a lot less when they get there because of the lack of gravity!

How much would you weigh on another planet?

This very cool interplanetary weight calculator on the Exploratorium website works out on your weight on all the planets and some stars too!

Density demonstration

Heavy objects are usually very dense. One very cool way to demonstrate density is by making a density column.

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If a planet is too close to its sun, it's too hot for life as we know it, too far away and everything is frozen, but around each star there's a Goldilocks Zone where there is the potential for water on a planet's surface. As we know water is essential for life.

Is Earth a Goldilocks Planet?

Earth is known as a Goldilocks planet as it has a not too hot and not too cold climate which allows water to exist in all three states ( solid, liquid and gas ). This makes it perfect for life.

However, there are more factors at work than how close a planet is to its closest star. The hottest planet in our solar system is actually Venus as its thick atmosphere traps heat. Mercury which is closest to the sun is still extremely hot but rotates very slowly ( one earth day is 59 days on Mercury ) so the side of the planet facing away from the sun doesn't get much heat and as Mercury doesn't have much atmosphere to hold the heat, temperatures can reach as low as -300 degrees Fahrenheit on the dark side.

For scientists searching for life in other solar systems, the Goldilocks Zone ( where rather like the littlest bears porridge it's not too hot and not too cold ) around stars is a good place to start, but is be no means a guarantee of finding life.

The post What is a Goldilocks Planet? appeared first on Science Experiments for Kids.

Our Moon is the largest moon in the Solar System relative to its parent planet. It's thought to have been created about 4.5 billion years ago when an object a similar size to Mars called Theia crashed into Earth. The impact melted part of the Earth's rocky mantle, which together with debris from Theia was ejected into space where it clumped together to form the Moon. The Moon is trapped in Earth orbit by the Earth's gravity.

You've probably noticed that the moon seems to change shape over time. This is because the sun only lights up one side of the moon, the other side is dark. As the moon orbits the Earth, different parts of it are lit, which is why it seems to change shape. These different shapes are known as phases of the moon.

The Eight Phases of the Moon

New Moon

This is when the Moon is between the Earth and the Sun. The illuminated side faces away from the Earth, so we don't see it.

Waxing Crescent

A small sliver of the Moon can be seen.

First Quarter

The Moon looks like a half circle. Half its illuminated side is visible.

Waxing Gibbous

More than half of the Moon can be seen. Gibbous is when more than half, but not a full Moon, can be seen.

Full Moon

The whole of the illuminated side of the Moon faces the Earth.

Waning Gibbous

The illuminated part of the Moon starts to decrease. Waning means the illuminated part is decreasing.

Last Quarter

Half the illuminated side is visible again, but the opposite side from the first quarter.

We never see the far side of the Moon from Earth.

Why can we see the Moon?

The moon itself doesn't emit any light, what we're actually seeing is sunlight reflected off the moon. When we see the whole of the moon, this is called a full moon. When none of the moon is lit up, this is a new moon. As we start to see more of the moon after a new moon, this is called waxing. As we see less of the moon after a full moon, we say the moon is waning.

How long does the Moon take to orbit the Earth?

The moon takes 27.32 days to orbit the Earth, during which time we see all its phases. From new Moon to New Moon, it takes 29.5 days.

Phases of the Moon Activity Ideas

Chalk Academy has some lovely moon phase water colour paintings.

A popular way to demonstrate moon phases is with oreos.

Happy Tots Shelf has a fantastic moon phase learning toy.

We made moon phase cupcakes using chocolate cupcakes and ready to roll icing. The first and third quarter should have been a bit neater, but for a first try they worked pretty well!

What is the lunar calendar?

The lunar calendar measures time using the moon's phases, whereas the solar calendar uses the Earth's orbit around the sun. A lunar month is shorter than a solar month, so the lunar calendar doesn't fit our traditional year, leaving us 12 days short.

Why do you never see the far side of the Moon?

Only one side of the Moon can be seen from Earth, as the Moon rotates at the same rate that it orbits the Earth, this is called tidal locking.

Activities for learning about the moon

One fun way to learn about the moon's phases is to keep a moon phase log over a few weeks and watch how the moon's shape changes.

Note the date, time, and sky condition and sketch how the moon looks each day. Try to make your observations at a similar time.

Find out how craters are formed by dropping marbles into flour and cocoa powder.

Do you know what a moonquake is?

Did you know rainbows form on the moon?

I have lots of other easy space science experiments you might like too!

Science Concepts

• Moon phases
• Space
• Lunar Calendar

The post What causes the phases of the moon? appeared first on Science Experiments for Kids.

Nitrogen is an essential element for living organisms as it's needed to make proteins for growth and repair and other biological functions. Nitrogen moves through the air, soil and living organisms ( plants, animals and bacteria ) in a process called the Nitrogen Cycle.

Where is nitrogen found?

• In the air as a gas. About 78% of the air in our atmosphere is nitrogen, but it is generally not usable by animals and plants in this form.
• Plants in the form of proteins
• Animals in the form of proteins
• Animal and plant waste
• In the soil

Nitrogen is found in different states at various points of the cycle.

Atmospheric Nitrogen N₂

Nitrates NO₃

Nitrites NO_s

Ammonium NH₄

Stages of the Nitrogen Cycle

Legume plants ( peas, beans and clover ) are home to nitrogen fixing bacteria. These convert nitrogen gas to nitrates which are nitrogen in a form that plants can use to make proteins.

Non legume plants absorb nitrates from the soil.

Animals eat plants and so get their nitrogen from plant proteins.

Some nitrogen is passed back to the soil as bacteria decompose animal waste.

Free living nitrifying bacteria convert ammonium in the soil into nitrates.

Bacteria are a vital part of the nitrogen cycle as it is because of them that nitrates are available for plants to absorb via their roots. Plants cannot use nitrogen in its other forms.

Denitrifying bacteria in the soil convert nitrates back into nitrogen gas.

Nitrogen gas is also converted to nitrates by lightning!!

Nitrogen Cycle Facts

The process where bacteria convert nitrogen into ammonium is called nitrogen fixation.

The next process is called nitrification, this is where bacteria convert ammonium into nitrates.

Ammonification is the process where plant remains are converted from nitrates back to ammonium.

Plants need nitrogen to make chlorophyll which is needed for photosynthesis.

Nitrous Oxide is a greenhouse gas. Too much nitrous oxide can lead to acid rain.

How do humans impact the Nitrogen Cycle?

Combustion of fossil fuels releases nitric oxide into the air which combines with other elements to form smog and acid rain.

The use of nitrogen fertilisers introduces extra nitrates to the soil which disrupts the natural nitrogen cycle. Excess nitrogen leaches into groundwater where it can lead to excessive algae growth.

Similar posts

Make a water cycle model to learn about the water cycle.

The post What is the Nitrogen Cycle? appeared first on Science Experiments for Kids.

The Archimedes' Principle is a scientific law which explains why some objects sink and some objects float. Archimedes was one of the world's greatest scientists. He was a mathematician, inventor, engineer and astronomer, but is arguably most famous for his Eureka moment which led to the development of the Archimedes' Principle.

Buoyancy and Archimedes

Objects float or sink depending on their buoyancy.

What is buoyancy?

Buoyancy is how well an object floats in water or air. You can see buoyancy in action with our "Save the Superhero" activity. Or when we make a lemon sink!

Who was Archimedes?

Archimedes was a Greek mathematician and inventor. One day as he climbed into his bath tub he noticed the water rising as his body entered the water.

This observation led to the Archimedes' Principle.

What is the Archimedes' Principle?

The Archimedes' principle states that any object immersed in a fluid is acted upon by an upward, or buoyant, force equal to the weight of the fluid displaced by the object.

When an object is dropped into water ( or a person climbs into a bath or swimming pool ), some of the water is displaced. This means the water rises upwards as the object or person pushes the water out of the way.

At the same time, buoyancy is pushing up the object, which changes its weight. If the weight of the object in the water is heavier than the amount of water displaced, the object will sink!

If the weight of the object and the amount of water displaced are the same or the weight is less, the object will float.

In the superhero activity above the buoyancy of the figure is increased with the pool noodles which increase the amount of water displaced, but doesn't add much to the overall weight.

In the diagram below the buoyant ( upwards force ) acting on the object that floats is equal to the weight ( downward force ) of the fluid that is displaced.

Why is the Archimedes' Principle Important?

The principle is used probably more than you think. One obvious use is to make sure ships float at sea. Generally ships are made from metal with a hollow hull to allow even water displacement. Ships sink into water as far as the weight of water displaced is the same as the weight of the ship!

More about Archimedes

Did you know Archimedes is credited with being the first person to calculate pi to an accurate value?

The post What is the Archimedes' Principle? appeared first on Science Experiments for Kids.

The ocean looks blue because of how it absorbs sunlight.

Water absorbs the longer wavelength colours at the red end of the light spectrum and the short wavelength violet and ultraviolet light.

Blue light is absorbed the least and is scattered and reflected back into our eyes, which makes the ocean look blue.

The actual shade of blue of the ocean depends several factors:

• Depth of the water.

• Amount of sunlight.

• What's in the water. For example, if there's a lot of green plant life the ocean can look more green.

Find out more about the amazing properties of water with our fun collection of water science experiments.

The post Why is the ocean blue appeared first on Science Experiments for Kids.

Visible or white light is made up of a range of colours each with a different wavelength. One way to see the different colours is to use a prism to split the light. When white light enters the prism it slows down and changes direction. The amount the light changes depends on the wavelength. Red light changes direction the least and violet the most.

Visible light is the part of the electromagnetic spectrum we can see. Each colour has a range of wavelengths. Red has a long wavelength and low frequency and violet has a short wavelength and high frequency.

What is a prism?

A prism is a triangular block of glass or perspex which splits light into its constituent colours.

When light enters a prism it is refracted. Each colour of the spectrum is refracted by a different amount and the colours are dispersed ( spread out ) allowing you to see them.

A prism is a great way to demonstrate visually that white light is actually made up of 7 different colours.

How to split white light with a prism

What you need to split light

Triangular prism

White cardboard

Large sheet of white paper

Dark coloured cardboard

Tape or glue

Large tray or sheet of thick card

How to use a prism

If it's not a sunny day, you can use a torch.

Use the dark card to create a slit over a sheet of white card. Place the card so sunlight shines through giving a thin beam of light.

Place the prism over the light and rotate it until you can see the light split into the spectrum of colours.

Why does a prism split light?

White light, which enters the prism, is a mixture of different wavelengths, which get bent ( refracted ) by different amounts though the prism, allowing them to be seen separately.

Facts about light waves

Light travels in straight lines.

It takes 8 minutes and 20 seconds for light to reach Earth from the Sun.

Light waves can travel through a vacuum.

Visible light is a form of electromagnetic radiation.

Light waves are much faster than sound waves.

Wavelengths of the visible spectrum of light range from 400nm ( violet end ) to 700nm (red end ).

More learning activities about light

Find out how to make a rainbow using a hosepipe!

Reverse the direction of arrows with this easy light refraction experiment.

Learn about how light travels in straight lines by making a light maze.

The post How to Make a Rainbow with a Prism appeared first on Science Experiments for Kids.

Do you know why the sky looks blue?

Light from the sun is made up of all the colours of the rainbow. A rainbow in the sky is formed when sunlight is refracted and dispersed in drops of rain or mist which splits the white light into its constituent colours. Red light has the longest wavelength and blue the shortest.

Why is the sky blue?

Light always travels in straight lines unless something gets in its way. The Earth's atmosphere ( made up of a mixture of gases ) scatters light. Longer wavelength colours pass straight through the atmosphere, but blue light with its shorter wavelength is scattered and reflected back to our eyes, making the sky look blue!

Now you know why the sky is blue!!

What is a spectrum?

A spectrum is a band of colours formed when light is split into its component colours.

How do you split light?

Light can be split using a prism. You can usually see rainbows refracted in bubbles and through sprays of water too!

The seven colours of the spectrum are listed below in order of frequency. listed in order of their frequency. Red has the lowest frequency.

Frequency is the number of waves per second and is measured in Hertz.

red
orange
yellow
green
blue
indigo
violet

How to make a rainbow

You can make a rainbow at home using a prism, hosepipe or a mirror if it's not a sunny day.

Still feeling curious? Check out out other science questions for kids!

The post Why is the sky blue? appeared first on Science Experiments for Kids.

Do you think of cows and global warming in the same sentence? Most people think of carbon dioxide as the most troublesome greenhouse gas, but actually, methane is the more damaging of the two, as it traps much more heat than carbon dioxide.

Methane pollution is thought to cause around a quarter of the global warming the Earth is currently experiencing.

Do cows contribute to global warming?

Cows and Global Warming

When you hear the word methane, you probably think of cow farts, but cow burps are also a big contributor to methane levels in the atmosphere. Livestock ( cows, pigs, sheep and other animals ) are responsible for 14.5% of global greenhouse gas emissions!! ( source - United Nations’ Food and Agriculture Organization)

How many cows are there?

There are thought to be over 1.3 billion cows on the planet, which amounts to a huge amount of methane!

Breeding cows is very inefficient, as they are often fed maize and soy ( potential human food sources ) and need a lot of water and land.

If grazing land has been made available to cows by deforestation, this is a double blow, as when trees are felled, they release carbon dioxide gas, whereas living trees take in and store carbon dioxide through the process of photosynthesis.

However, before you assign all the blame to cows, humans are actually responsible for most methane emissions.

Sources of Methane

Decaying vegetation

Livestock and farming

Leakage from industrial processes ( the oil and gas industry is thought to create ⅓ of emissions ). Read more about this here.

Plastic bags - studies have shown that plastic releases methane at several stages of its life.

Microorganisms feeding on vegetation also release methane. This is exacerbated by melting permafrost, leading to the thawing of vegetation, which wouldn't normally be available for microorganisms to feed on.

How can we reduce methane emissions?

Reducing plastic usage is a good start, and we're already seeing fantastic steps forward with this. WWF has some great tips for changing how we use plastic.

Scientists are exploring ways to reduce emissions from cows, including feeding them specialised diets.

The world going meat free probably isn't the answer as this article explains.

If you want to learn more about greenhouse gases, check out our candy greenhouse gas models too!

The post How do Cows Contribute to Global Warming? appeared first on Science Experiments for Kids.

We've all heard about climate change, but what is it, and how can we teach our children about it? First, children need to be informed, and second, they need to feel empowered, to feel like they can make a difference. Remember, lots of small actions add up to a big result.

What is Climate?

Climate refers to weather conditions ( rainfall, wind, temperature ) over a large region and over time. When we talk about the weather, we usually mean what the weather is like on that day or week. For example, the overall climate in Britain is temperate with cool winters and warm summers, but the weather can be cold in summer for a short period of time. Weather is generally local and temporary.

What is Climate Change?

Climate Change ( sometimes referred to as global warming ) is the process of our planet heating up. This is largely caused by deforestation, burning fossil fuels and farming. The Earth is warming up faster now than in any other time period we know about.

How much has the Earth's temperature increased?

Did you know the average temperature on Earth has increased by 1°C in the last century? That might not seem like much, but oceans cover 70% of our planet, and it takes a lot of energy to heat all that water, as well as air and land. So, a one degree increase in the average global temperature is a big thing!

Rising temperatures don’t just mean that we’ll get warmer weather, the increasing temperatures will make worldwide weather more extreme. Some areas will get wetter and some drier. Animals and humans could start to find it difficult to adapt to their changing climate. Low lying coastal regions could flood or disappear as sea levels rise as the ice caps melt.

How do we know the climate is changing?

Scientists know that the Earth's climate has warmed up and cooled down several times over millions of years, but the current temperature increase is happening much faster than previously known.

The main reason Earth is getting warmer is an increase in greenhouse gases in the atmosphere. Greenhouse gases ( for example, Carbon Dioxide and Methane ) trap heat from the sun in the Earth's atmosphere, contributing to its warming.

Why are greenhouse gases increasing?

Humans burning fossil fuels is a big contributor to the increase in carbon dioxide in our atmosphere.

How do scientists know what the Earth's climate was years ago?

One way scientists can tell what the Earth's climate was like in the past is to study ice cores.

Ice cores are tubes of ice taken from deep below the surface of the ice today. Scientists can analyse the bubbles in each layer to calculate how much carbon dioxide they contain.

Rising sea levels also tell us that the climate is warming up, and this isn't just due to melting ice caps. As the oceans warm up, water expands, too!

Why does it matter that Earth's climate is changing?

Over millions of years, Earth's climate has warmed up and cooled down many times. However, today, the planet is warming much faster than it has in any other time period.

Even a small increase in global temperatures can have a huge impact on the health of the plants and animals on our planet.

What can we do to halt climate change?

There are lots of small actions individuals can take to help.

Change the way you travel

Reducing how much you use a car is one of the most effective measures a single person can take. Using public transport more or switching to an electric vehicle is a great start.

Aeroplanes also contribute massively to increasing carbon dioxide levels, so holidaying locally and generally travelling less is another good way to reduce carbon emissions.

Eat Less Meat

A person who reduces their animal protein consumption by half also reduces their carbon footprint by 40%! Isn't that incredible?

Avoid Fast Fashion

Choose good quality clothes that will last a long time rather than fast fashion that's not worn for long.

Shop locally

By shopping locally, you can reduce the number of miles your food travels and therefore your carbon footprint.

Reduce plastic usage

Shop thoughtfully. Don't buy heavily packaged products. Yes, they will still be on the shelves for now, but if everyone stops buying them, perhaps the manufacturers will change their processes.

Take a stand and refuse to buy plastic toys that won't get used.

Take your own reusable containers to supermarkets, and if you buy a lot of hot drinks, a reusable cup is a great investment.

You could argue that one person eating less meat, buying less plastic and not going on holiday abroad isn't going to make any difference to climate change, but people follow the example of others, so by setting a good example to family and friends and speaking out about your actions YOU can actually end up making a huge difference around the world.

Learn about Climate Change - Hands on Science

Demonstrate melting polar ice caps with this melting ice activity.

Learn about greenhouse gases and make edible models.

Take a look at my collection of FREE climate change resources.

This Earth toast is a great visual activity from Left Brain, Craft Brain.

Find out how cows contribute to global warming.

The post What is Climate Change? appeared first on Science Experiments for Kids.

Fresh ice feels sticky because when you touch it, the ice immediately freezes the moisture in your skin, which makes the ice feel sticky to touch!

A great way to learn about the properties of ice is to try some ice experiments!

When using ice with small children always leave it to melt a little first so the surface is slimy NOT sticky.

Science Sparks Ice Experiments for Kids

Ice is a lovely surface to paint on as children can paint, wipe clean and paint again!

Ice excavations are great fun and you can be as creative as you like when setting them up.

Discover part of the reason the Titanic sank with this iceberg investigation.

Find out why salt melts ice and how this is used in real life situations with an ice and salt experiment.

Use your new ice and salt knowledge to make frost appear on the surface of a tin can or supercool a drink quickly.

Did you know you can also use the freezing power of ice and salt to make ice cream in a bag?

Try some sporty science with an ice hockey investigation to find the best material for an ice hockey puck.

Hot ice is tricky to make but impressive if you can get it to work.

Do you have any ice experiments to share with us?

The post Why is Ice Sticky? appeared first on Science Experiments for Kids.

Have you ever looked up at the moon and wondered about its pockmarked landscape? Craters are fascinating geological features that give a small insight into the history of our solar system.

This is a great ( and very easy ) activity for discovering how craters are made. Did you know the moon's surface has millions of craters, varying from just a few metres across to hundreds of kilometres?

What is a crater?

A crater is a bowl-shaped depression formed by the impact of a meteorite, volcanic activity, or an explosion. Craters are found throughout our solar system and beyond.

Examples of craters in our solar system

The Moon has a heavily cratered surface.

Mercury's surface is heavily cratered. The lack of atmosphere means impacts are frequent, as asteroids don't burn up as they travel towards the surface.

Many asteroids and moons in the solar system also have craters.

Many craters still exist on Earth, including Meteor Crater in Arizona, Chicxulub crater in Mexico, and the Chesapeake Bay crater. Many craters on Earth have been eroded over time and are no longer visible.

Making Craters Activity

This activity shows children how dropping marbles from a greater height creates a bigger impact crater.

You'll need

A shallow metal pan

Plain white flour

Cocoa powder

Ruler

Marbles and different sized balls.

Making Craters with Marbles

Fill the tray about 2 cm deep with flour, and lightly sprinkle the cocoa powder over the top to cover the entire surface.

Drop the marbles into the tray. The marbles represent crashing asteroids and comets.

Create craters using different size balls and marbles.

Measure and record the size of the crater for each ball.

You should find that if you drop marbles of the same size from different heights, the one with the furthest to fall will make the largest crater as it is moving faster, so it has more energy when it hits the surface, creating a deeper depression.

Why do craters form?

The surface of the moon is marked by millions of craters, varying from just a few metres long to hundreds of kilometres long. Most formed a long time ago when comets, asteroids and meteorites crashed into the moon's surface.

Craters on Earth

Barringer Crater ( also known as Meteor Crater ) in Arizona was created instantly when a 50-meter (164-foot), 150,000-ton meteorite slammed into the desert around 50,000 years ago.

The Chicxulub Crater, off the Gulf of Mexico, is thought to be the impact site of the meteor, which wiped out or contributed greatly to the extinction of the dinosaurs at the end of the Cretaceous period 65 million years ago.

Mount Erebus in Antarctica has a lava lake in its summit crater.

Read more about the biggest craters on Earth on Live Science.

What is the oldest crater on Earth?

The oldest ( and largest ) impact crater on Earth is the Vredefort crater in South Africa. It is estimated to have originally been 185 miles (300 kilometres) across. A huge meteorite or asteroid created this giant crater 2.02 billion years ago!

Creating Craters Instructions

More Space Science Experiments for Kids

If you enjoyed this activity, you'll love my other space science experiments, including rocket mice, space sensory trays, water bottle rockets and straw rockets! Most of them only need items you probably already have in the house. What are you waiting for?

If your children love space, my book This IS Rocket Science has lots of brilliant space-themed experiments and activities! I'd love for you to take a look.

The post How are craters made? Science Activity appeared first on Science Experiments for Kids.

Most people think of the North Star ( Polaris ) as being the brightest star in the sky, but there are actually many stars much brighter.

The reason Polaris is so important is because the axis of Earth is pointed almost directly at it, meaning Polaris does not rise or set, but remains in almost the same spot above the northern horizon all year while the other stars circle around it. This means that in the Northern Hemisphere Polaris is relatively easy to find in a northerly direction.

If you were at the North Pole, where do you think the North Star would be?

The North Star would be directly overhead.

How to find the North Star

Polaris is part of the constellation of Ursa Minor, also known as Little Bear or Little Dipper.   Polaris lies at the end of the handle of the Little Dipper and is by far the brightest of the seven stars.

What is a constellation?

A constellation is a group of stars which form a recognisable pattern. These are traditionally identified with a mythological figure.

Glow in the Dark Constellations - How to find the North Star

We made glow in the dark constellations using glow in the dark paint and black card. This was a great way to visualise each constellation and a lot of fun in the dark too!

Materials

Glow in the dark paint

Black card

Sticky stars - optional

Instructions

Choose a constellation to represent and use the glow in the dark paint to draw the stars as dots on your black paper.

Can you ask a friend to guess what each constellation is in the dark?

Can you tell what these three constellations are?

More constellation activities for kids

MollyMoo has some beautiful constellation sewing cards.

Try some dot to dot constellations from These Moments at Home.

Steam Powered Family has some lovely pipe cleaner constellations.

Did you know?

Polaris has not always been the North Star. The Earth wobbles on its axis as it rotates, which means over time, it points to different stars. In 3000 BC, The North star was Thuban!

Now you know how to find the North Star!

If you enjoyed this, try some more of our space science activity ideas.

The post How to find the North Star appeared first on Science Experiments for Kids.

Nicolaus Copernicus was a Polish astronomer born in February 1473 who realised that the Earth orbits the Sun. This idea was strongly opposed at the time as many people believed objects orbited around a central Earth.

The model proposed by Copernicus was called Heliocentrism.

What is Heliocentrism?

Heliocentrism ( helios means Sun ) is where the Sun is motionless at the centre with other planets rotating around it in circular paths. We now know that this is absolutely how things work, and it seems very obvious, but Copernicus didn't have the tools we have today. His ideas marked the beginning of modern astronomy.

Facts about Nicolaus Copernicus

• Copernicus was also a physician, scholar, economist, translator, mathematician and artist!
• Nicolaus Copernicus was born on February 19th 1473.
• His theory of Heliocentrism was proposed in his book De revolutionibus orbium coelestium

• The chemical element Copernicum (symbol Cn and atomic number 112 ) is named after Copernicus.
• Nicolaus Copernicus was one of the great polymaths of his time. A polymath is someone brilliant at lots of different things. Aristotle, Archimedes and Leonardo Da Vinci were also great polymaths.

This easy activity helps children visualise how the Sun, Earth and Moon move around each other to demonstrate Nicolaus Copernicus's theory.

Heliocentrism Activity for Kids

Materials

Black cardboard

Yellow, blue and grey paper or card

Stapler

Instructions

You'll need three children to take part in the demonstration. One will be the Sun, one the Moon and one the Earth.

Make three hats to represent the Sun, Earth and Moon using cardboard and a stapler or glue.

Ask the Sun to stand in the centre and the Earth to walk around the Sun in a circle. The Moon should then walk around the Earth in a circle as the Earth circles the Sun.

More Heliocentrism Ideas

How many other planets can you add to your demonstration?

Try thinking about how long it takes the Moon to orbit the Earth and how long it takes the Earth to orbit the Sun and ask the children to change their walking speed to reflect this.

Create a moving model of the Sun and Earth to show how the Earth orbits around the Sun.

If you enjoyed this activity, don't forget to look at my other solar system activity ideas.

If you want to discover more science activities based around the discoveries of famous scientists we have those too!

The post Who was Nicolaus Copernicus? - Theory of Heliocentrism appeared first on Science Experiments for Kids.

Why does salt melt ice? We've experimented with ice and salt before and found that salt does make ice melt faster, but do you know why? Salt lowers the freezing point of water which sounds complicated but actually makes a lot of sense once you try it out!

The photo above is just a block of ice with pipe cleaners and straws frozen inside for decoration. You can see that the ice has started to melt where we've added salt.

Why does salt melt ice?

Salt lowers the freezing point of water.

Ice melts faster when salt is added as the salt lowers the freezing point of the water, this is known as freezing point depression. The more salt you add the lower the freezing point.

This interesting feature of salt and ice can be used for lots of fun and easy experiments.

Making ice cream with ice and salt

Did you know you can make ice cream using milk, salt and ice?

This works because as the ice melts heat is absorbed from the surroundings ( the milk mixture ) making it freeze.

See our full instructions for making ice cream with ice and salt here.

This would also make a great taste investigation. Try adding different flavours to the milk and investigate to see whether a friend can guess what each flavour is. You could even add some strong flavours like chilli or garlic!

How to cool a drink quickly

This investigation uses salt to supercool an ice and water mixture cooling the drink inside very quickly!

How to make frost

Making frost on a can is easy if you have salt, ice cubes and a tin can. This is our Frosty the Snowman, but you could theme this investigation however you wanted.

More ice investigations

Try some painting on ice. This is one of my favourite ice activities as ice is a lovely medium to paint over.

Make some ice decorations and hang them outside.

Investigate how to make the best ice hockey puck.

Try some colour mixing and make slushy drinks with ice.

Make some baking soda ice cubes and vinegar and watch them fizz.

Rainy Day Mum investigates salt melting sheets of ice and why we grit roads.

Can you think of any more icy investigations?

The post Why does salt melt ice? appeared first on Science Experiments for Kids.

Following on from our solar system-themed activities is this easy layers of the Earth model made with play dough. My 7-year-old wasn't very impressed when I showed him my composition of the Earth model, but once I carved it open, he declared it to be 'quite cool'. It's not perfect and not really to scale ( the play dough was quite squishy, but it clearly shows the inner core ( marble ), outer core ( orange ), mantle ( yellow) and crust ( green ).

Five minutes later, everyone was wrapping play dough around a marble, trying to copy my Earth model, so I think it was a success and a fun way to show children what's inside the Earth.

Layers of the Earth Model

Composition of the Earth

Earth's Inner Core

Did you know the inner core is a huge metal ball about 2,500 kilometres wide. The metal stays solid because of a massive amount of pressure surrounding it.

Temperature: 5,000°C - 6,000°C

State: Solid

Composition: Iron and nickel

Earth's Outer Core

Did you know the liquid outer core is 5150 kilometres deep, and the movement of the metals in this layer creates the Earth's magnetic field?

Temperature: 4,000°C – 6,000°C

State: Liquid

Composition: iron, nickel, sulphur and oxygen

Mantle - The mantle is actually split into two parts.

Earth's Lower Mantle

The lower mantle is found between 670km and 2,890km below the Earth's surface.

Temperature: 3,000°C

State: solid

Composition of the lower mantle: iron, oxygen, silicon, magnesium and aluminium

Earth's Upper Mantle

The upper mantle is 670km below the surface of the Earth. The rock here is stiffer than the lower mantle because it is not as hot.

Temperature: 1,400°C – 3,000°C

State: liquid/solid

Composition of the Upper Mantle: iron, oxygen, silicon, magnesium and aluminium

Earth's Crust

Temperature: Around 22°C

State: Solid

Composition of the Earth:

The oceanic crust ( beneath the ocean bed ) is made up of iron, oxygen, silicon, magnesium and aluminium.

The continental crust ( land ) is made up of granite, sedimentary rocks and metamorphic rocks.

Image taken from This Is Rocket Science

More space science experiments for kids

Find out how the Universe is always expanding, make film canister rockets, straw rockets and lots more space science activities with my collection of space experiments designed for World Space Week.

You might also like my FREE downloadable space experiment pack that I used for a special space week in school full of even more great space science experiments for kids.

I also have a space science book with 70 space-themed activities and investigations taking kids into space, around the solar system and back home again, all while learning about the forces and obstacles astronauts must overcome for a successful trip.

The post What is inside the Earth? appeared first on Science Experiments for Kids.

A sign of autumn is when leaves on some trees start to change colour. The green colour starts to fade to be replaced by red, orange or yellow. Do you know why leaves change colour in autumn?

Why do leaves change colour in autumn?

Plants make energy through a process called photosynthesis. They convert carbon dioxide from the air, water and sunlight into energy and oxygen. A chemical pigment called chlorophyll absorbs the sunlight for photosynthesis and also gives the leaves their green colour. There is so much chlorophyll in the leaf that it masks the other colours, such as carotene, which is yellow.

In autumn, when the temperature starts to drop, the tree severs the connection with the leaves, and the chlorophyll breaks down, revealing the other colours in the leaves. Eventually, the leaves fall to the ground. We call these trees Deciduous.

Examples of deciduous trees are maple, birch and oak trees.

Why do some trees stay green?

Some trees stay green all year round. We call these Evergreen trees. These trees keep their leaves all winter and so still need chlorophyll to make energy. You'll notice that the leaves on Evergreen trees are usually smaller and often have a waxy layer, which helps prevent water loss in the winter. They also produce a chemical which stops them freezing! How clever is that?

Examples of evergreen trees are pine trees, cypress trees, Douglas Fir, Colorado Spruce.

Learn more about autumn with my easy autumn STEM challenges!

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Lemons float on water, but do you know how to make a lemon sink?

This fun science trick will baffle your friends and is a great way to learn about density!

Photo taken from Snackable Science

What you need to make a lemon sink

Bowl

Water

Lemon or orange

We tried pushing a lemon down to make it sink, but it just popped up again.

What about if we chop it into smaller pieces?

I expected these small bits to sink, as without its waterproof skin, water can get into the lemon pulp and add to its weight, but our segments still floated.

We then removed the skin and found the small bits of lemon sank. Why do you think this is?

Why do lemons float?

If you look at the inside of the lemon skin, you can see it is very thick and porous, this means it contains lots of air which makes it float.

Which other fruits do you think will float, and which sink?

Can you predict which fruits will sink and which float and test them?

Why do objects float in water?

Density plays a part in why some things float and some sink. Objects that are more dense than water sink, and those that are less dense float. The inside of the lemon is denser than the skin, so the inside of a lemon sinks, but a whole lemon floats thanks to the air bubbles in the skin.

When an object floats, it pushes the water out of the way ( displacement ). Have you ever noticed that when you climb into a bath, the water level moves up? That’s because your body displaces the water upwards.

More science for kids in the kitchen

Try one of my other exciting kitchen science experiments, including finding out why pineapple stops jelly setting, making meringue and even a butterfly life cycle.

Make a lemon battery!

Use your lemon rind to make and test a fruity boat.

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Today we have an investigation for little astronomers to demonstrate how the universe is expanding.

Did you know we are part of a spiral galaxy called the Milky Way? Earth is located in an arm of the spiral.

What is the Universe?

When we talk about the universe, we mean everything that exists. Galaxies, planets and everything in between. Scientists think the edge of the universe is expanding faster than the speed of light!

How big is the Universe?

It's hard to imagine just how big the universe is. Scientists estimate that there are around 100 billion galaxies!! If you think the Milky Way ( our galaxy ) is thought to have between 200 and 300 billion stars like our sun, it's pretty impossible to comprehend.

Much of the universe is actually empty space ( dark matter and dark energy ) and the things we can see ( ordinary matter ) make up only 4-5% of the universe.

What is dark matter?

Scientists think stars and planets would not move as they do in empty space, but so far we don't have the ability to see or measure dark matter. Dark matter is thought to make up between 25-28% of the universe.

What is dark energy?

Dark energy is how scientists refer to the force that is thought to be behind the expansion of the universe. Dark energy is though to make up between 67-70% of the universe.

Universe Expansion Theory Demonstration

This is a very simple experiment to demonstrate the Universe expansion theory.

You'll need:

A balloon

Clip

Black Marker

How to demonstrate the expansion of the universe

• Blow up the balloon so its about the size of an orange.
• Clip it with a balloon clip.
• Draw dots on the balloon with a black marker, these represent the the milky way galaxy.
• Remove the clip and keep blowing up the balloon.
• What happens to the dots?

How does the universe expand - explanation

The balloon is a model of the universe, which is constantly stretching outwards. The universe has been expanding ever since the big bang about 13.8 billion years ago.

More Space Science Experiments for Kids

Discover how craters are formed on planets with this crater investigation.

Even very small children will love our rocket mouse!

Find out when the Earth formed and how we know!

Science concepts

The big bang

Universe

Dark matter

The post How does the Universe expand? appeared first on Science Experiments for Kids.

Why does food rot? Have you ever noticed that if you leave an apple (or any fruit ) for too long, it starts to rot or decay? This can lead to a lot of food waste, so it's important to understand how to store food items so they last as long as possible.

Why does food rot?

Food rots because micro-organisms such as bacteria, yeasts and fungi feed on the fruit and break it down. Have you also noticed that keeping fruit and vegetables in a fridge makes them last longer? This is because the cold slows down the growth and reproduction of microorganisms, slowing their decay.

How to preserve apples

This simple science activity investigates ways to stop apples from spoiling without a fridge!

What you need for an apple rotting experiment

• One apple
• 4 containers
• lemon juice
• vinegar
• salt water ( 1 tablespoon salt dissolved in hot water )

Apple rotting investigation instructions

• Cut the apple into 4 even pieces.
• Place a segment of apple into each container.
• Cover each apple with the same amount of either lemon juice, vinegar or salt water. Leave one just exposed to the air     ( this is the control ).
• Leave untouched for about a week in a cool place and observe the differences.

Apple rotting investigation results

Control Apple - you can see this has started to shrivel up, but there is not much evidence of mould.

Apples preserved with salt and vinegar ( vinegar is at the front )

Apples preserved with lemon juice

How can you stop food from rotting?

There are many mechanisms for preserving food. All slow or stop the activity of micro-organisms which make the food decay.

As well as refrigeration, you can freeze, can or pickle foods to preserve them.

You can see from the photos that in our investigation, the apple segment in the salt is the best preserved. This is because salt draws the moisture out of the food, so the micro-organisms do not thrive and cannot reproduce as fast as they can in other conditions.

The vinegar did prevent mould growth. This is because vinegar has anti-microbial properties. It inhibits or kills the microorganisms that lead to mould on the surface.

You can see that the lemon juice shows evidence of mould. This could be because the micro-organisms have flourished in the sugary environment.

More food preservation ideas

Can you think of other things to try? What about bicarbonate of soda? Or other fruits?

The Free Range Life has some great ideas for preserving peppers you could test too!

More kitchen science experiments for kids

These egg experiments are fantastic fun!

Find out how to transform egg white into beautiful meringue!

Make your own rock candy!

Or, go all out and have a Science Bake OFF!!

The post Why Does Food Rot? appeared first on Science Experiments for Kids.

Yeast is a living single celled organism commonly used in baking. Yeast is a type of leavener ( baking soda and baking powder can also be used as leavening agents ). Yeast converts sugar and starch ( from the sugar and flour in the bread mix ) into carbon dioxide and ethanol. The carbon dioxide gas makes the dough rise. Yeast works best in a warm, moist environment, which is why it's best to leave the dough somewhere warm to rise. This conversion of sugar into carbon dioxide and ethanol is called anaerobic respiration.

We can see respiration occurring in yeast when we make bread or pizza dough.

Note - respiration in yeast is anaerobic respiration - this means it doesn't use oxygen

Pizza Dough Respiration Investigation

Pizza dough ingredients

500g Strong White Flour

7g Yeast (Fast)

1tbsp caster sugar

330ml Luke warm water

1 tsp salt

1tbsp olive oil

How to make pizza dough

• Mix the yeast, sugar and water in a jug and put to one side.
• Sieve the flour into a mixing bowl and add a pinch of salt.
• Gradually add the water until a nice elastic dough is formed.
• Knead the dough well, strong flour will take a lot of effort to get nice and elastic, so work it hard.

Leave it somewhere warm, we left ours in the airing cupboard for about an hour. Look how much it increased in size.

Once risen, knead the air out of the dough again and roll it out to make your pizza bases.

We turned our pizza into a plant cell model. The green peppers are chloroplasts!

More Yeast Experiments

Did you know you can use the power of yeast to blow up a balloon? First blow up the balloon and let the air out. Pour a packet of yeast, warm water and a tablespoon of sugar into a small bottle and quickly pop the balloon on top. Give the mixture a shake and you should find the balloon blows up thanks to the carbon dioxide gas produced by the yeast.

The post What is Yeast? appeared first on Science Experiments for Kids.

Elasticity is the ability of an object to return to its original shape after being subjected to a force ( for example, being stretched, pulled, squashed or twisted ). Elastic objects bounce back to their original shape very quickly!

What is elastic distortion?

Elastic distortion is when an object returns to its original shape when the force is removed. An example is when you stretch a hairband, which returns to its original size and length when you stop stretching it.

A spring is another example of an object that can be elastically distorted.

What is inelastic distortion?

Inelastic distortion is when an object doesn't return to its original shape and size when the force is removed. A cardboard box that has been crushed doesn't return to its original shape when you stop squashing it.

The point at which an object changes from being able to distort elastically to inelastically is called the elastic limit. An overstretched spring will not return back to its original size.

The amount of extension of an elastic object is directly proportional to the force. This is Hooke's Law.

What is elastic potential energy?

When you stretch an elastic band, energy is stored in the band, called elastic potential energy. The more the elastic band is stretched, the more potential energy it has.

Experiments to demonstrate elasticity

Elastic band catapult

Lollypop sticks or pencils

Lots of elastic bands

A small bottle top

Glue or tape

Instructions

There are lots of different ways to make a catapult.

The video above shows you how to make a very simple craft stick catapult, or you could make a more complex version like the picture below.

How does it work?

Test the catapult by launching different size balls and experiment by pulling the lever down all the way, halfway and just a little bit. You should find the more the elastic band is stretched, the greater the amount of elastic potential energy it stores, which is then converted to kinetic energy in the ball.

The more energy transferred to the ball, the further it will travel!

More Elasticity Investigation Ideas

Build a bigger catapult with a longer arm and investigate to find out if a longer arm means more power.

A stretchy spring investigation is a great way to learn about elasticity!

Our elastic band powered boat is another way to demonstrate elastic potential energy and kinetic energy.

Build an elastic band powered LEGO car like Frugal Fun for Boys and Girls.

We love these stixplosions from Babble Dabble Do.

A simple shoebox catapult is another excellent way to demonstrate elasticity!

Science concepts

• Elastic energy
• Inelastic distortion
• Elastic distortion
• Kinetic energy
• Hooke's Law
• Elastic potential energy

The post What is Elasticity? appeared first on Science Experiments for Kids.

Today's experiment is very simple. We made some ice cubes and then put them in different places to watch them melt. This is a great activity for learning about melting and freezing!

You can use standard ice cubes or any shaped moulds you have around the house.

Melting ice cubes learning objectives

Discover that water changes state depending on its temperature.

Experiment with different materials to find out which is the best insulator.

What you need

• Ice cubes of the same size
• Containers for the ice cubes.

Instructions

• Place each ice cube in a container.
• Put the ice cubes in different places, we put ours outside, inside and in the fridge.
• Time how long it takes each to melt.

First, we discussed what makes ice melt and predicted where the cubes would melt the fastest.

Can you design a table to record your results?

What does it mean when something melts?

Melting is when a substance changes from a solid to a liquid. Water freezes to form ice when it is cooled to below 0^oC, when ice is warmed to above 0^oC it melts and turns back into water.

To expand this experiment, you could try leaving the ice cubes in more places, or observe and photograph at 10-minute intervals.

Recording the temperature in each place would also be useful.

Our Results

The first time we did this, the cube outside melted faster than the one inside. We decided there could have been a few reasons for this, one being that the outside ice might have been smaller than the inside one, or the weather had an impact.

We tried again on a different day and found, as expected the cube inside melted faster than the one outside.

More fun science for kids

What do you think would happen if you covered your ice cubes with bubble wrap or foil? Can you investigate? One way to slow down the speed at which ice melts is to protect it from warm air. Insulating materials are good for this! Try wrapping an ice cube in bubble wrap, paper towel or kitchen foil and timing how long each takes to melt.

Another easy investigation is to use a pipette to drip warm and cold water over ice cubes to investigate if warm and cold water speed up the melting process.

Try freezing small plastic items inside ice cubes to set up an icy rescue!

If you enjoyed this activity, try one of my other ice experiments.

You can also find more ice experiment ideas in my collection of easy ideas for science at home!

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