I usually do this viscosity experiment using different liquids such as water, oil, ketchup and treacle. This version is a special syrup filled investigation for pancake day!

The idea is that you record how long it takes different delicious pancake syrups to flow down a ramp. Thicker ( more viscous ) liquids will flow more slowly than thinner ( less viscous ) liquids.

Pancake Syrup Viscosity Experiment

You'll need

Chopping board to use as a ramp

Stopwatch

Liquids to test - maple syrup, golden syrup, honey, chocolate sauce, yoghurt etc

Chalk or marker

Pancake Syrup Viscosity - Instructions

Mark a start and finish line on the ramp or use my handy sheet.

Pour the syrupy liquids down the ramp one at a time.

Start the timer as the liquid passes over the start line and stop when it passes the finish line.

Repeat for each test liquid.

Repeat three times for each liquid and calculate the mean value.

Make the investigation a fair test

Keep the ramp at the same gradient.

Use the same amount of each liquid.

Only time between the start and finish line.

Make it large scale!

I made this giant ramp with cardboard and sticky-back plastic ( contact paper ) for a school science fair a few years ago. It worked really well, as we could wipe it clean between different groups using it.

More Pancake Day Activities

Find out why we eat pancakes on Shrove Tuesday.

Experiment with different raising agents to find your perfect pancake mixture.

Or, try one of my other easy edible experiments.

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Easter is fast approaching, so it's the perfect time to try some of our Easter STEM Challenges! We've been busy testing these for you over the last couple of weeks and would LOVE to see the creations of your little scientists, so do share photos with us on Facebook, Instagram or Twitter. I've also got 100s more easy everyday science and STEM activities you might like.

Top tip for STEM Challenges

My biggest tip for a successful STEM Challenge is to keep it simple. Simple STEM challenges are much easier for kids to complete, and as a parent, I know how difficult it can be if you need to go out and buy lots of science materials.

Easter STEM Challenges

Eggy Zip Wire

The idea behind this activity is to build a harness to transport an egg down a zip wire. This is a great activity for learning about friction and changing gradients. To investigate, try changing the type of string used to make the zip wire. A rougher string means more friction between the harness and zip line.

We usually set this up outdoors between two trees, but it works well inside, too.

Save the Egg

For this activity, children need to wrap an egg so well that it survives a drop down the egg chute. We used a long cardboard tube for our chute, but if you don't have a tube, drop it from shoulder height.

This is a great activity for making use of recycled materials, too.

Remember to drop all the packaged eggs from the same height to make it a fair test.

How much does an egg weigh?

Using a small balance scale, investigate how many plastic eggs weigh as much as a chocolate egg. Children can also measure and compare different types of eggs.

Magnet Powered Egg Cars

Put a magnet inside a plastic egg and use magnet power to make a car move. This is a brilliantly simple Easter STEM challenge!

Eggy Toothpick Towers

Try to build a tower strong enough to support an egg using toothpicks and plasticine. This activity is good for encouraging children to think about strong shapes.

Catapult an Egg

Build a craft stick catapult to catapult a plastic egg. We've been making egg-shaped targets to shoot the eggs through, too!

Egg Chain Reaction

We love making chain reactions! For this Easter version, we created a chain reaction using a chocolate egg instead of a ball. We used dominoes, a plastic pipe and a toy car, but you can use anything you have around the house.

A chain reaction is a great open-ended STEM challenge with lots of opportunities to be creative and inventive.

Pneumatic opening egg

This simple pneumatics based STEM challenge uses two syringes and a piece of plastic tubing to open a shoebox decorated like a chick inside an egg.

Finally, I've created a set of easy Easter STEM Challenge printable cards you might like!

More Easter STEM Challenge Ideas

The Educator's Spin On It shows you how to build egg towers.

Inspiration Laboratories has a fun launching eggs activity.

Find out how many helium balloons it would take to lift an empty egg and then an egg with something inside.

Can you hide different objects inside plastic eggs and ask a friend if they can guess what's inside by the noise it makes?

Or, try one of my other Easter science ideas.

Can you think of any more egg STEM challenges?

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Do you like to dunk a biscuit in a hot drink or a glass of milk? Do you find some biscuits are better for dunking than others? Personally, I'm a big fan of the chocolate digestive to dunk. The combination of melted chocolate and soft biscuit is the best!

What makes a good dunking biscuit? Do you like to dunk a biscuit more than once, or do you prefer one dunk to give the perfect melty texture?

We designed an investigation to find out which type of biscuit is best to dunk. Everyone can probably agree that a biscuit breaking and landing in the drink is never a good thing, so we placed six different biscuits in hot water and timed how long each took to collapse.

We chose to test typically British biscuits, but you can use any type you want.

Biscuit dunking science investigation

I've created a biscuit dunking challenge investigation sheet to record results and write up the investigation.

Which is the best biscuit to dunk?

We found the shortbread biscuit could be dunked the most number of times without breaking and was the last biscuit to collapse in the cup of water test.

So, if you want a sturdy biscuit that can be dunked more than once, choose a shortbread-style biscuit.

Extension tasks

Repeat the activity using cold water and compare the times with hot water.

Dunk the biscuits in a warm cup of tea to find out if they behave differently than in cold water?

If you enjoyed this activity, take a look at my other delicious edible experiments!

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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.

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If you want to know whether an egg is fresh or bad, there's a very simple test you can do at home. All you need is a container and some water!

How to tell if an egg is bad

Pop the egg in question into a bowl or glass of water at room temperature. A fresh egg will sink and lie on its side, and an old egg will float.

If the egg sinks but lies at an angle, it's not as fresh as one that lies horizontally, but it is most likely still okay to eat.

Why do bad eggs float in water?

Eggs that are stale or bad float because they have an air pocket inside. As an egg ages, moisture leaves the egg and is replaced by air, which increases the size of the air bubble. If the air pocket becomes big enough, the egg will float.

Other ways to tell if an egg has gone off

If you open an egg and it smells a bit funny, the chances are it's gone bad and should be thrown away.

Shake the egg and listen carefully. If you can hear the insides sloshing around, it's probably past its best.

Shine a bright torch at the egg and look for cracks in the shell or air gaps inside.

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If you want to eat a chocolate bar on a hot day, a Cadbury's Flake is a good choice! We tried REALLY hard to melt one and couldn't do anything more than slightly soften it.

How can you melt a Cadbury's flake?

Place it in a bowl over simmering water.

Didn't work.

Heat it in a pan.

This didn't work, even when we crushed it into little bits.

Put it in a hot oven

I confess to forgetting about this one until the burning smell reached my nose. It burned but didn't melt...

Microwave it

Still didn't melt.

Why doesn't a Cadbury's Flake melt?

According to Science Focus, the arrangement of fat and cocoa solids in a flake is different from normal milk chocolate, so the melting fat cannot lubricate the cocoa and make it flow.

Now you know why we use flakes in ice creams. The ice cream will melt in the sun, but not the flake.

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Baking soda and baking powder can be easily confused. They have a similar function and name but work differently. Both are used to add air to mixtures, usually bread dough and cake mix. They are leaveners.

The key difference is baking soda ( sometimes known as bicarbonate of soda ) needs an acid to work, and baking powder needs heat and moisture to be activated.

Baking Powder - contains sodium bicarbonate and cream of tartar ( an acid ).

Baking Soda - contains just bicarbonate of soda.

You can see that baking powder has an inbuilt acid, so it's ready to work immediately.

Mixtures that use baking soda are usually those that are used straight away, for example, pancake mix, as the baking soda starts to work as soon as the acid is added.

The reaction between baking soda and vinegar is often used for science experiments as it instantly makes bubbles which froth up.

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Almost everything to do with food and cooking involves science. Food is kept in a fridge to slow down the growth of microorganisms, some foods are preserved in vinegar others are kept in the dark. Bitterness in food and drink can be reduced by adding salt. Need to ripen a banana fast, no problem, pop it in a paper bag!

Whatever the problem, there's usually a science based kitchen hack to solve it!

Six of the best science based kitchen hacks

1. Extra Fluffy Eggs

Do you know you can make eggs extra fluffy by adding a little soda water?

Add two tablespoons of soda water to 3 eggs and mix well. Then, cook the omelette as usual.

Why does it work?

When the egg and soda water mixture is heated, the air in the soda water bubbles expands, giving you an extra light and airy omelette!

2. Butter from Cream

If you've run out of butter but have cream, you can make butter! All you need is some strong arms and patience.

Pop the cream in a jar with a lid. Close the lid tightly and shake. After 5-10 minutes, you'll have delicious fresh butter.

Why does this work?

Cream is a type of mixture called a colloid. It is made up of very tiny particles of fat dispersed in water. When you shake the cream, the fat particles stick together, forming butter.

3. Save the fruit salad

Stop a fruit salad from turning brown and wilting by covering it in fruit juice. Orange juice or a little lemon or lime juice works well.

Why does it work?

Many fruits are rich in iron; when you cut them, the inside is exposed to oxygen in the air. The iron in the fruit reacts with oxygen to give the familiar brown colour. The process is called enzymatic browning. Anything that prevents the exposed fruit from coming into contact with the air will stop or slow the reaction.

The addition of an acid lowers the pH of the fruit, which slows down enzymatic browning as it inactivates the enzyme responsible for the reaction.

4. Stop raisins sinking

Have you ever made a fruit cake and found all the raisins sink to the bottom? Raisins have an oily, slippy surface, which means they sink through the cake mix as it starts to cook.

If you cover the raisins ( or other dried fruit ) in a little flour before adding them to the mix, they can grip the cake batter better and don't all sink to the bottom.

Image taken from Snackable Science

5. Ripen an avocado

We've all been there, you pull an avocado out of the fridge, and it's hard...what can you do?

The answer is simple. Just place the hard avocado in a paper bag with a banana or kiwi, and it'll soon be beautifully soft and ready to eat.

Avocados are a climacteric fruit. They continue to ripen after being picked. Strawberries and grapes are non-climacteric. They don't ripen after being picked.

Why does this work?

Avocados release ethylene gas slowly, which makes them ripen. The paper bag traps the ethylene gas, ripening the avocado faster. Bananas and kiwis also release ethylene gas, so having them in the bag with the avocado speeds the process up even more!

If you want to ripen a banana, pop that in a paper bag for a day too!

6. Chill a drink in 5 minutes

Need a cold drink fast? No problem. Add some salt to an ice bucket along with ice and water, and you'll have a cold drink in less than 5 minutes.

Why does this work?

Salt lowers the melting/freezing temperature of ice. This makes the water temperature drop below zero ( freezing point depression ). When salt is added to the icy water mixture the ice starts to melt. Melting requires energy. The ice absorbs heat energy from its surroundings ( the water and drink ) to melt. This makes both the water and the drink in the water get cold very quickly!

Know your baking soda from your baking powder

These two common kitchen ingredients can be easily mixed up. Remember baking soda needs an acid to activate it. Baking powder starts to work straight away as it contains cream of tartar, which is an acid!

More kitchen hacks based on science

Find out why you should always salt pasta water.

If you want nicely browned meat, make sure it's dry before cooking. Meat won't brown until the water evaporates, so a quick pat with some kitchen towel will give you the lovely browned meat you want!

When your gravy is too runny, mix a little cornflour ( cornstarch ) with water and stir it in. The gravy sill soon be deliciously thick.

If you want to stop the tears when cutting onions, try popping them in the freezer first, or make clean, sharp cuts to reduce the damage to the cells that release the tear-inducing chemicals.

If you enjoyed reading my science kitchen hacks, you'll love my kitchen chemistry experiments!

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If you're looking for a fun science experiment to do in the kitchen, you've landed in the right place! These five easy milk science experiments use milk as the main ingredient.

Make ice cream with milk, ice and salt. Find out how to make butter from cream ( not quite milk ), make glue from milk, create colourful explosions in a tray of milk and make a little ornament from milk. These simple science activities are great fun and use items you probably already have in your kitchen!

Milk Science Experiments for Kids

Make ice cream from milk

Did you know you can make homemade ice cream in a bag in less than 10 minutes with just milk, salt and ice? You don’t even need a freezer!! Add your own flavourings, make a delicious snack and learn about the freezing power of ice and salt at the same time.

Glue from milk

All you need to make glue from milk is milk, white vinegar and baking soda. The vinegar is used to split milk into curds and whey. This fun kitchen science experiment is very simple but requires adult help to heat the milk.

I wouldn't use the milk glue for anything important, but it's fun to make the glue and then set up an investigation to test how strong it is.

Make butter from cream

Did you know you can make butter from cream? This is a super simple way to make butter at home, but it does require a bit of effort. You'll need good quality double cream, a jar and some very strong arms for this fun kitchen hack!

Create an ornament from milk

This activity also involves using vinegar to split milk into curds and whey. You can then squash the curds and make a small ornament! This activity is sometimes called making plastic milk.

Colourful magic milk explosions

You'll need whole milk, food colouring and a little dish soap to create these fantastic milky colour explosions. Older children can use this activity to learn about emulsions, too!

If you have any more ideas for science experiments using milk, let me know!

More kitchen science experiments for kids

123 Homeschool also has some brilliant plastic milk creations.

Challenge your friends to a kitchen science bake off! Learn about the role of yeast when making dough, discover how to bake ice cream in an oven without it melting and find out why cakes turn a lovely brown colour.

My eggy science experiments are lots of fun, too. You can remove the shell of an egg with vinegar to learn about tooth decay, make an unbreakable egg and even a bouncy egg!

If you prefer candy to eggs and milk, you'll love my candy science experiments!

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Easter is just around the corner, so I've put together a collection of egg experiments perfect for this time of year. Eggs are great for experiments as they are inexpensive, easily available and very versatile. We try not to waste food at Science Sparks, but for most of these ideas, you can still eat the actual egg. However, be careful if you have a child with allergies.

Don't forget to check out my ever-growing selection of printable science experiments too!

Egg Experiments for Kids

Egg Drop Experiment

My Humpty Dumpty themed egg drop experiment is great fun. We used sealable sandwich bags filled with different materials to put the egg inside, but another way to do it is to make a parachute or create a container for the egg and drop that.

Unbreakable Egg Experiment

Find out how to make an unbreakable egg. All you need is an egg, and some cling film. We're sure you'll be surprised at how strong an egg actually is!

Egg Experiments with Vinegar

Find out how to make an egg shell disappear! This is like magic! Watch the shell disappear before your eyes. Just be careful not to break the membrane like we did.

Once you've dissolved the shell with vinegar, you can make the egg bounce! Be warned, it might break!

How to shrink an egg

Make an egg shrink and then expand, but first, you'll have to remove the shell to expose the delicate membrane. This is a brilliant visual way to learn about osmosis!

How strong is an eggshell?

Do you think an eggshell is strong or weak? This activity uses eggshells to make a bridge that books can be piled on top of. The shells might be stronger than you think!

Egg in a Bottle

Find out how to force an egg into a small bottle or jar. Watch as the egg drops into the jar like magic. This clever activity works because of differences in air pressure.

Meringue Experiments

Find out what happens when you whisk egg white and why. This one is a bit messy but lots of fun and very yummy!

Once you've perfected your meringue skills, have a go at making a Baked Alaska. This clever dessert allows you to put ice cream in the oven without it melting.

The image below is taken from Snackable Science

Make an Egg Float

Do you know how to make an egg float and we don't mean by letting it go bad!

Eggs as Teeth

Did you know eggs are great for learning about teeth as the shell is made from a similar material? Try soaking eggs in vinegar, coffee or tea to discover what happens.

Egg Vehicles

Create a vehicle to protect an egg in a collision. You could use LEGO, K'Nex or any other materials you like.

Egg Experiments eBook

My new egg experiments eBook contains five brilliant egg investigations that are easy to follow and also great fun.

More egg experiments

Find out how to tell if an egg is boiled or not by spinning it.

Can you think of any more Egg Experiments for us?

If you've got an egg decorating competition coming up, these easy decorated eggs might be helpful, too!

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This easy magic milk science investigation is fantastic fun for kids of all ages. All you need is whole milk, food colouring and a little dish soap to create crazy colour explosions. Older children can use this activity to learn about emulsions.

The reaction that gives the colourful display is between the fat molecules in the milk and dish soap. This is why whole milk is the best to use.

How to set up a magic milk investigation

You'll need

Whole milk

A shallow tray

Food colouring

Pipette

Washing up liquid ( dish soap )

Instructions

1. Pour a layer of milk into your baking tray or plate.

2. Gently drip a few drops of food colouring onto the surface of the milk - spread these out.

3. Add drops of the washing-up liquid on top of the food dye and watch what happens.

Safety: Do not drink the milk after.

What do you think of our magic milk display?

Why does it work?

Think about why we use dish soap in everyday life. It's to clean our dishes and break down the fat that makes them greasy. Milk is mainly tiny droplets of animal fat dispersed in water; whole milk has a higher fat content than semi-skimmed, which is why it's the best one to use. The washing-up liquid/dish soap breaks down the fat in the milk. We call it an emulsifier as it allows the water and fat to mix, creating an emulsion. The emulsifier (dish soap) molecules have a water-loving head and a water-hating tail. The tail sticks into the fat droplet and surrounds it, leaving only the water-loving heads. This allows the fat to mix with the water! While doing that, it scatters the food colouring molecules, giving the colourful display you see.

Properties of emulsions

Emulsions are thicker (more viscous) than oil or water and have many uses thanks to their unique properties.

Examples of emulsions in the kitchen

Salad dressings

Ice Creams

Other examples are paint and some cosmetics.

Immiscible liquids

Immiscible liquids are those that don't mix to form a solution.

Examples of Immiscible liquids

Vegetable oils do not dissolve in water. We can use this property of oil and water to make a density jar.

If a mixture of oil and water is shaken and then left to stand, tiny droplets of oil float upwards, and eventually, the two liquids will separate: a layer of oil will form on the surface of the water. However, if an emulsifier is added to the oil and water, a mixture called an emulsion forms, and the oil and water do not separate.

Extension task for magic milk experiment

Try testing different dish soaps to see if they all have the same effect.

Experiment with whole, semi-skimmed and skimmed milk.

Try one of my other exciting chemistry experiments.

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Do you know how to make a lava lamp? DIY lava lamps are one of our favourite science experiments as they are super simple to make, can be used over and over again, and you can be as creative as you like with them. We've made Minions, reindeer and even snowmen lava lamps!

Lava lamps are also a safe, exciting and visual way to introduce chemical reactions and the often tricky concept of density to children ( the oil floats beautifully on top of the water ).

How to make a lava lamp

What you need to make a lava lamp

• A clear plastic or glass bottle or jar
• A bottle of vegetable oil
• Water
• Alka Seltzer
• Food colouring (a bright colour is best!)

DIY Lava Lamp Instructions

Fill the bottle about a quarter full with water. Top up with vegetable oil to the (near) top.

The oil and water should separate into two layers, water at the bottom and oil on the top.

Once the oil and water have separated, add enough food colouring to achieve the colour you want. The colour will mix with the water at the bottom.

Pop in half an Alka Seltzer tablet and watch the bubbles form. Add more Alka Seltzer little by little to keep the bubbles rising and falling.

Top Tips for making a DIY lava lamp

Try using effervescent vitamin tablets instead of Alka Seltzer; these are usually a bit cheaper and have the same effect, although they might colour the water slightly.

More science experiments to try

What happens if you use half a tablet? Or two?

Once the reaction has finished, try gently tipping the bottle on its side. What do you notice?

Why do homemade lava lamps work?

Alka seltzer is made of citric acid and sodium bicarbonate, which react with the water to form carbon dioxide gas and sodium citrate. It is the bubbles of carbon dioxide that carry the coloured water into the oil, giving a lava lamp effect.

NOTE - Please supervise the use of Alka Seltzer and effervescent vitamin tablets.

Why do oil and water separate?

Water and oil do not mix. This is because water is a polar molecule - its structure means it has a positive charge at one end and a negative charge at the other. Water molecules stick together because the positive end of one water molecule is attracted to the negative end of another. Oil molecule structure is different - it is non-polar, meaning that its charge is more evenly spread out, so the oil is not attracted to water. We call it hydrophobic (water-fearing), as it tries to get as far away from water as possible and does not mix. Oil rests on top of the water rather than underneath because it has a different density to water.

More DIY lava lamp ideas

How about a pumpkin themed lava lamp for Halloween? These make a great last-minute pumpkin or a fun alternative if you don't fancy carving one this year.

We had a lot of fun making our Minion version of a lava lamp. If I did this again, I'd use blue water at the bottom, as you couldn't see the yellow very well in the oil.

Or how about a Christmas Lava Lamp? Our reindeer and snowman were super cute and a big hit with the kids last year.

If you enjoyed this activity, you'll love our other experiments for kids. We have hundreds of science-based investigations and activities, with something for all interests and ages.

The Royal Institution has an excellent lava lamp and other fab experiments, too!

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Today's post is part of my United States of Science series. The idea is you print a map of the USA and colour each state as you learn about it with a fun science activity.

New York

New York City in the state of New York is the most populated city in the whole of the United States, with a population of over 8.5 million people.

The Statue of Liberty is just one of the iconic landmarks in New York City. It's made of copper, which has oxidised naturally to form a green patina coating which actually protects the copper underneath.

It took about 20 years for the Statue of Liberty to change from copper coloured to green!

Why is the Statue of Liberty Green?

Some simple copper chemistry will help us to find out. Copper coins can be cleaned with vinegar and salt.

What you need to clean coins

Vinegar

Salt

Small bowl

Copper coins

How to clean coins

1. Put about a teaspoon of salt into a bowl

2. Add about 50ml of vinegar and stir to dissolve the salt.

3. Leave the coins in the vinegar and salt solution for 5 minutes.

5. Take them out and compare them to other dull copper coins!

You now have sparkling copper treasure!

Why does vinegar clean coins?

The reason copper coins don't stay shiny is that the copper reacts with oxygen in the air to form copper oxide, which is a dull greenish-grey colour.

When you mix salt (sodium chloride) with vinegar (acetic acid), sodium acetate and hydrogen chloride form. Hydrogen chloride is an acid which works well at rapidly cleaning the surface of the copper coin, leaving it beautifully shiny and removing the oxide.

If the coin is exposed to the air again, it will quickly react with oxygen to form the dull greenish copper oxide layer.

The Statue of Liberty is coated in a thin layer of copper which has turned green due to reactions with air and water.

Now you know why the Statue of Liberty is green!

This activity would be great for a school science fair project.

If you enjoyed this activity, don't forget I have lots more fun Chemistry science experiments for kids of all ages!

How else can you clean coins?

Anything acidic will clean coins, and if it's acidic and salty, even better!

A fun way to extend this investigation is to try to clean copper coins with other substances. Ketchup, coke and lemon juice are all good things to try first!

Do not eat or drink anything you've used to clean coins.

New York Facts

The Statue of Liberty gets struck by lightning multiple times a year.

New York is nicknamed The Empire State.

The capital city of New York is Albany, not New York City!

New York is bordered by Pennsylvania, New Jersey, Connecticut, Massachusetts, Vermont and Canada!

Niagara Falls borders New York and Canada.

The post New York - Why is the Statue of Liberty Green? appeared first on Science Experiments for Kids.

An easy way to make salt crystals is to dissolve table salt in water and leave the solution somewhere warm until the water evaporates, leaving behind sparkly salt crystals.

We also made coloured salt by adding a little food colouring.

This activity and more salt science experiments can be found in a salt science activity sheet made as part of a collaboration with the Primary Science Teaching Trust.

You'll need

Table Salt

500ml warm water

Bowl or jug

Spoon

Plate or shallow bowl

Food colouring - optional

How to make salt crystals

Put about 500ml of warm water into the jug.

Stir in a large spoonful of salt and stir until it is all dissolved ( when you can't see or feel the grains any more ).

Keep stirring in salt a spoon at a time until you reach the point where no more salt will dissolve ( we call this a saturated solution ).

Pour a small amount of the salty mixture onto a flat bowl or plate and leave it somewhere warm. Outside in the sun is ideal.

After a few days, you should see crystals appear.

How to make coloured salt crystals

Make as above but add a little food colouring to the saturated salt solution.

Why do salt crystals form?

When you stir salt into warm water, it dissolves. It looks like the salt has disappeared, but it has actually mixed with the water to form a transparent solution.

When the salty solution is left in a warm place ( we left ours on a windowsill ), the water evaporates, leaving behind salt crystals.

Evaporation of water happens when water gets enough energy to change state from liquid water to water vapour ( a gas ).

Extension Tasks

Water evaporates faster when there is a bigger surface area. This is because more water is exposed to the air. Try leaving the same volume of water in a tall container and in a shallow bowl. The water in the shallow bowl should evaporate faster than the water in the tall container.

More Science for Kids

Use salt to cool a drink quickly!

Make ice cream also using the supercooling power of salt.

I've also got lots of easy kitchen science ideas for you to try!

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Lemons are a small, yellow citrus fruit that taste sour, smell good and can be used for lots of very simple science experiments as they are acidic.

I've collected 5 of my favourite science experiments using lemons for you to try at home. All are very easy and don't use many resources other than the lemon!

Make a lemon sink

Lemons have a thick, porous skin which allows them to float, but there is a way to make a lemon sink. You just need to remove the skin!

Make a lemon battery

The juice inside a lemon can act as an electrolyte in a lemon battery!

You'll need copper wire or a copper coin and a zinc ( galvanised ) nail to make a battery with a lemon.

Blow up a balloon with lemon juice

Lemon juice is acidic, if you mix it with an alkali ( base ) such as bicarbonate of soda the two will react to neutralise each other releasing carbon dioxide gas as a by product.

If you add a little lemon juice to a clean, empty bottle, and then pop a bit if bicarbonate of soda into a balloon and place the balloon on top of the bottle so the bicarbonate of soda ( baking soda ) tips into the lemon juice, the carbon dioxide released will fill the bottle and then inflate the balloon!

Make fizzy lemons

Make fizzy lemons by adding a little baking soda directly to half a lemon and mixing it. Add a little food colouring for more colourful, fizzy fun.

Drop a lemon into a glass

Learn about the law of inertia with this easy demonstration of Newton's First Law.

Make homemade lemonade

Use lemons, baking soda and water to make your own fizzy lemonade! You can find a super easy recipe for this in Snackable Science.

Invisible ink with lemon juice

Create your own invisible ink with lemon juice. This is a very simple science activity that is great for kids of all ages. Older children can experiment with lemons, limes and other acids. Write a message on white paper with lemon juice and then place in an oven to reveal it!

Can you think fo any more science experiments using lemons for us?

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If you're thinking of trying a science activity at home for the first time, or are a more seasoned kitchen scientist, red cabbage indicator is perfect! The humble red cabbage is great for making colour changing potions, testing the pH of different things around the kitchen and generally a great introduction to science at home, chemical reactions and acids and alkalis!

Using red cabbage indicator to test pH

You'll need

3 transparent containers

Water

White vinegar

Baking soda ( bicarbonate of soda )

Jug

Sieve

Red Cabbage

Stove

Spoon

Instructions

Make red cabbage indicator by boiling a handful of chopped red cabbage in water for about 5 minutes and leave to cool.

Drain the mixture keeping the purple liquid. This is the indicator!

Pour the same amount of water into each container.

Add a tablespoon of vinegar to one container and a tablespoon of baking soda to another container. Mix well.

Don't add anything to the third container.

Pour a little red cabbage indicator into each container and watch as the liquid changes colour!

You should get something a little like this!

Experiment with different concentrations of vinegar and baking soda to create different shades of green and pink.

Red cabbage contains flavin ( an anthocyanin) . Flavin is a natural pH indicator which changes colour depending on the pH of the solution.

Don't forget to try my other red cabbage experiments too!

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Next time you boil up some red cabbage, make sure you save the liquid as it can be used for lots of easy science experiments.

This red cabbage breath test is a fun twist on the more traditional testing the pH of different substances, although why not do both?

Did you know you can even make your own pH testing paper using red cabbage indicator?

You'll need

A handful of red cabbage

Pan

Stove or hob

Water

Straw

Transparent container

Sieve or colander

Instructions for a red cabbage indicator breath test

Boil a handful of chopped red cabbage in a pan of water. The water should turn purple after a few minutes.

Leave the pan to cool and drain the contents, saving the pink/purple liquid.

Pour the liquid into a transparent container.

Using the straw blow into the red cabbage indicator liquid. It should turn red, indicating that something in your breath is acidic!

Why does red cabbage indicator change colour when you breathe into it?

Red cabbage contains a natural pH indicator called flavin which is an anthocyanin. Flavin changes colour depending on the pH of the solution.

You can see from the red cabbage indicator pH scale below that it turns red in the presence of an acid and green/yellow in the presence of a base ( alkali ).

We breathe out carbon dioxide which is acidic, this is why the indicator turns red when you blow into it.

If you've still got some red cabbage indicator left, try testing different ingredients from around the kitchen to see if they are acidic or alkaline.

Who created the concept of the pH scale?

The concept of the pH scale was introduced by a Danish chemist called Soren Sorensen in 1909.

If you enjoyed this, you'll love the rest of my kitchen chemistry science experiments!

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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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Here are Science Sparks we're passionate about making science fun for kids and where better to have fun than the kitchen! Have you ever wondered how a bowl of cookie dough turns into a crisp delicious biscuit or how thick, stretchy dough becomes light fluffy bread? It's all about the science! The science of baking is quite complex, there's probably a lot more going on than you realise.

If you've ever accidentally forgotten the baking powder or baking soda, you probably didn't get the light airy dough you were hoping for and too much baking powder gives a funny taste. Baking is all about getting the amounts of each ingredient and the cooking time and temperature right for your bake.

I've got five Bake Off masterpieces ( or not ) which are perfect for exploring science in the kitchen.

Plant Cell Pizzas

I know it doesn't sound very appealing, but just look at this!

Making pizza dough is a brilliant way to learn about yeast. Without this clever ingredient your pizza base would be flatter than a pancake with no baking powder.

Baked Alaska

Baked Alaska is one of those dishes that always seems too difficult to make, but with a bit of preparation ahead of time it's a super easy and very impressive dessert.

The idea behind a Baked Alaska is that it's a hot dessert fresh from the oven with a cold, ice cream centre. How does it work? The answer is in the meringue. Meringue is full of air bubbles which allow it to act as an insulator around the ice cream protecting it from the heat of the oven. Luckily meringue doesn't take long to bake so the ice cream remains frozen. YUM!!

Meringue Tower

Find out why egg white transforms so magically into meringue with these easy meringue towers. Add cream and fruit to make a delicious dessert.

Honeycomb

Honeycomb is very easy to make and tastes delicious. The key ingredients are golden syrup which gives honeycomb it's distinctive colour and baking soda which gives it a bubbly texture. Try our easy honeycomb recipe to make your own tasty treats. Will you crush it and sprinkle over ice cream or add your own toppings?

Make your own butter

Butter is used in lots of baking recipes, but did you know you can make your own butter from cream?

Science of Baking - Bake a Cake

There's a huge amount of kitchen science in cake baking. The end result depends on the combination of ingredients and how they are cooked.

Flour in a Cake

Most cake recipes use wheat flour. When water is added to flour, gluten forms. Gluten is a strong, stretchy protein which gives structure and shape to baked items.

Gluten is made up of two proteins gliadin and glutenin. When bread is made they form strands which link together to form a network. It's this gluten network that strengthens the dough and creates pockets of air helping to give bread its light airy texture.

When you knead dough you're making the gluten network stronger. If you don't knead enough and the gluten network is weak the bread will flop and if you over knead making the network too strong the dough won't rise enough.

Top Tip - High protein flours are good for making bread, which is why bread flour isn't great for cake making. Bread flour has a higher protein content than standard self raising flour. Flour with a low protein content is best for cakes and pastries that you want to crumble.

Leavening Agents

A leavening agent is something that makes a cake or dough lighter by adding air to the mixture. Baking soda, baking powder and yeast are all example of leavening agents.

How does yeast work in baking?

When yeast is used in bread making it uses sugar for a process called respiration which releases carbon dioxide. It's these bubbles of gas that make the dough rise.

Baking Soda as a Leavener

Baking Soda ( bicarbonate of soda ) reacts with acidic ingredients in the mix. Recipes which use baking soda often also have a cider vinegar or another acid to react with the baking soda. The reaction between baking soda and an acid also creates carbon dioxide.

Steam as a Leavener

Steam is also a leavening agent. Ingredients such as butter contain water, when heated the water turns to steam and expands, making the mixture rise.

Eggs to add air into a mixture

If you've ever made meringue you'll know that whipping up egg whites adds air into the mixture. When baking a cake you don't want as much air as in meringue, but if egg whites are whipped a little and carefully folded into cake batter the bubbles in the egg add air to the mixture. Air expands when heated which makes the cake lighter and fluffier.

Egg as an Emulsifier

Egg yolks contain a protein called lecithin which binds the cake together. This is because lecithin is an emulsifier, it allows fats and water to mix ( they usually repel each other ).

Sugar and the Maillard Reaction

You might think sugar just makes a cake taste sweet, but it's also responsible for how a cake smells and how it browns. A reaction between amino acids ( building blocks of proteins ) and sugar produces flavour and the brown colour you see when a cake is fully baked. This reaction is called the Maillard reaction.

That's it, five great Science Bake Off Masterpieces and five great ways to learn in the kitchen!

If you'd rather something less sweet, try my three course meal of science!

If you enjoyed this post you'll love my brand new book Snackable Science which is bursting with delicious edible experiments.

Snackable Science contains 60 easy edible experiments for kids, including making your own sour sherbet, homemade jelly babies, cell model cupcakes and lots more edible science experiments.

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What can you do with red cabbage?

Firstly, you could eat it? Boil it, make coleslaw or stew it with apples, or how about some red cabbage science experiments?

To make red cabbage indicator all you need to do is slice a small amount of red cabbage and boil it for about 5 minutes until the water turns purple. Leave to cool and carefully sieve the mixture to remove the cabbage!

Red Cabbage Indicator

Learn about acids and alkalis with a simple red cabbage indicator.

Colour Changing Potions

Make magical colour changing potions with red cabbage indicator.

pH Indicator test strips

Make your own pH indicator test strips using red cabbage indicator and filter paper.

Frozen Red Cabbage Indicator

Try freezing any leftover red cabbage indicator and placing it on a plate of a mild acid or alkali ( lemon or lime juice or baking soda dissolved in water work well ).

Red Cabbage Indicator Breath Test

Find the pH of your breath with using red cabbage indicator!

More chemistry experiments for kids

Try one of my collection of the best chemistry experiments for kids!

Make a beautiful density jar!

Babble Dabble Do has a brilliant elephant toothpaste activity.

This collection of fun kitchen science experiments will keep kids busy for weeks!!

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Red cabbage indicator is a simple way to tell whether a substance is an acid or alkali.

Acids can be found in the food we eat, in our bodies and around the home. Some acids, especially those found in cleaning products, can be very harmful, so take care when using them and always read their hazard labels.

Alkalis are a group of chemicals that react with acids. Substances such as soap are alkalis and bicarbonate of soda, which we use in baking, and also harmful things like bleach are alkalis.

You can make a straightforward red cabbage pH indicator to determine whether a substance is an acid or alkali. This activity is a great way to introduce the pH scale to kids!

How to make a red cabbage pH indicator

What is a pH indicator?

We use a substance called an indicator to test the pH of something. An indicator will change colour in the presence of an acid or alkali. The pH scale goes from 0 to 14. A substance with a pH of 0 is a strong acid, pH 14 is a strong alkali, and pH 7 is neutral.

You can make an indicator using red cabbage.

What you need to make a red cabbage indicator

• Red cabbage - chopped
• Water
• A saucepan
• A sieve
• Cups or small containers
• Different substances to test - baking soda, vinegar, lemon juice and lime juice all work well.

Method

Place the chopped cabbage into the pan and cover it with water.

Simmer for 10 minutes.

Sieve the water and cabbage into a jug - you will notice that the cabbage liquid is very purple.

Leave to cool for about 30 minutes.

Add a small amount of each test substance to a separate cup or container, and try to keep the amount of test substance the same.

Use a pipette to drop about 20ml of red cabbage indicator into each cup and record the colour the indicator changes to.

Safety note

Wear safety goggles if using strong acids/bases.

An adult should help with the chopping and heating of the cabbage.

Red Cabbage Indicator pH Colours

Universal Indicator pH colours

Notice that the colours for acids and alkalis are different when using a universal indicator.

Results

When using the red cabbage indicator, the colour of the liquid will change from purple to red if it is an acid and from purple to green if it is an alkali. The different shades of colour will depend on the strength of the acid or alkali. The substance is said to be neutral if there is no colour change.

How does the pH indicator work?

Acids and bases are opposites; acids have a low pH, and bases have a high pH.

Red cabbage contains a pigment called anthocyanin, which is what changes colour.

More Red Cabbage Indicator Experiments

Make colour changing fizzy potions!

Make your pH test strips by soaking filter paper in red cabbage indicator and leaving it to dry. Once dry, cut the filter paper into strips and dip it into test substances. Try testing milk, fizzy drinks or soap. Can you predict their pH before testing?

Try using beetroot juice instead of red cabbage; which works best?

You could also try blowing into the indicator. What happens?

A pH indicator can also be made from red poinsettia leaves!

What happens when you blow into the red cabbage indicator?

The indicator should turn red as the carbon dioxide you breathe out reacts with the water to form carbonic acid.

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The kitchen is a great place to try some edible science experiments, did you know you can even create a whole meal of science experiments? Cooking involves a huge amount of science, and the best thing is you can usually eat the experiment afterwards so there's no waste, just a lot of fun!

Today's challenge is to create a menu with three courses ( and some extras if you like ) all of which can be a mini science experiment or investigation.

I've made a simple menu planner so you can get organised ready to create your meal!

If you enjoy science in the kitchen or are looking for even more ideas, I'd love you to check out my book, Snackable Science which contains 60 awesome edible experiments for kids!!

Three Course Meal of Science Experiments

Take a look at my ideas below and choose something for each course. You can print the menu planner above to write down everything you need and use the super science menu below for any guests!

Super Starters/Appetizers

Homemade Bread and Butter

Serve homemade bread ( learn about yeast ) and butter made from cream.

Add different herbs to the butter and investigate to find out if your guests can tell which is which from the smell.

Magical Main Courses

Pizza

Find out about yeast and respiration by making a pizza. We made a plant cell pizza to learn about plant cell structure at the same time!

Try our hula hoop food group activity to create a perfectly proportioned meal!

Delicious Desserts

Amazing Baked Alaska

Impress your guests by putting ice cream in the oven without it melting! This fun kitchen science trick uses the insulating power of meringue to protect the ice cream from the heat of the oven.

Super Cool Ice Cream in a Bag

Create an ice cream sundae in a flash with flavoured milk using the cooling power of ice and salt.

Fruity Cream, Strawberry and Meringue Towers

Find out why egg white and not egg yolk is used in meringue with these delicious meringue towers.

Jelly and Pineapple

Find out which fruits stop jelly setting with this easy investigation. The fruit you choose depends whether you like your jelly/jello set or runny!

Drinks Menu

Slushie Drinks

Serve slushies made using the same method as the ice cream sundaes. As an extra task you could create drink holders that insulate the person's hands from the cold drink.

Hot Chocolate and Melting Marshmallows

Finish your meal with a delicious hot chocolate and melting marshmallows.

One way to carry out this hot chocolate experiment is to set up different temperatures of drink. Make sure they are not too hot to drink. Cold, warm and hot ( but drinkable ) temperatures work well.

Another idea is to make hot chocolate sticks by melting chocolate and letting it set in a mould ( great for learning about changes of state ) and placing the hot chocolate stick in cold, warm and hot milk. Add some crushed peppermint, marshmallows or sprinkles to make it extra special!

Special Filtered Apple Cider

Learn about filtering with this special apple cider recipe!! This is lovely chilled in summer or served warm with cinnamon in winter.

Meal of Science Experiments - Special Extras

Extra Crunchy Gingerbread Houses

You could even serve a gingerbread house on the side. Which sticky substance will stick it together the best, will it be icing sugar, liquid glucose or even melted marshmallows?

Delicious Peppermint Creams

Finally, finish your magical meal of science experiments with chocolate covered ( always good for learning about changes of state ) peppermint creams.

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This viscosity experiment is a fun way to discover how different liquids flow. Or just to have a race with ketchup and other kitchen ingredients!

The rate at which different fluids flow can vary considerably, this is called resistance to flowing viscosity.

We did this on a big board in the garden, but it works just as well on a much smaller scale. Chopping boards make a really good ramp.

Viscosity Experiment for Kids

What you need

• Ramp - chopping board or paper covering something else.
• Stopwatch
• Liquids to test: we used oil, water, corn syrup, passata, treacle and ice cream sauce.
• We used old yogurt drink bottles as containers for the liquids.

We carefully considered the best way to time the different liquids. Initially, we thought we would let them all run down the ramp at the same time and see which reached the bottom first, but we decided it would be too hard to release them all at the same time and difficult to time. So, we drew two lines on the ramp and recorded the time taken for each liquid to pass between the lines.

Viscosity Experiment Instructions

• Pour the liquids down the ramp one at a time.
• Start the timer as the liquid passes over the first line and stop when it passes the second.
• Repeat for all liquids.

Make your own ramp

If you're doing this in a school or with lots of children, a wipe-clean ramp is a good idea. I made this one for a school science fair by covering a big sheet of cardboard with contact paper (sticky back plastic ).

Let's make it a fair test!

The same volume of liquid should be used for each substance. We used 50ml.

Only start the timer once the liquid has passed the first line.

If the ramp falls over mid experiment, make sure it has the same gradient as before to keep the test fair.

Repeat the test 3 times for each liquid and find the average time.

More Easy Science for Kids

There's a similar activity in Snackable Science where we race different kinds of ketchup to investigate whether different brands flow at different speeds.

If you enjoyed this experiment, we've got lots more easy outdoor science experiments and investigations you might like and some great kitchen science experiments too!

More kitchen science experiments

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Here at Science Sparks we love hands-on science experiments and if you can eat them afterwards so there's no wastage then even better! I've pulled together my top 10 awesome edible experiments for you to try below. I would love to see your creations and ideas too!

Awesome Edible Experiments

Build and test a candy house

This mini science project is a favourite of kids everywhere. One idea is to start the activity in the supermarket to look for the best shape and size sweets and biscuits to use for the house. You'll also need to find a sticky substance to hold the candy house together.

A gingerbread house is a fun variation of this too!

Edible Butterfly Life Cycle

An edible butterfly life cycle is a great way to learn about the life cycle of a butterfly. If you don't want to make a sweet version, dried pasta also works nicely.

The post includes a free printable so you can just add the decorative parts.

Edible DNA Model

DNA has a really interesting structure which can be hard to visualise. This edible DNA model makes that easy!

Upside Down Toast

Next time you have toast for breakfast turn it into an investigation to find out why toast lands butter side down?

Orange Peel Plate Tectonics

Learn about the Earth's tectonic plates with an orange!! An edible earthquake investigation is a great follow on activity too!

Edible Cell Models

Cell structure can be a tricky thing to learn about, but not with these jelly cell models! If you don't want to use jelly, sweets on a plate work just as well! Don't forget the cell membrane!

Bake Ice Cream without it Melting

Do you know how to bake ice cream in an oven without it melting? The secret is to cover it with meringue which is a brilliant insulator and protects the ice cream from the heat of the oven for a short period of time.

Ice Cream in a Bag

Making ice cream in a bag is one of those childhood classic experiments that everyone should try at least once. It's a great summer camp activity or school science experiment.

Homemade Slushy Drinks

Make your own slushy drinks on a hot day to learn about melting and changes of state.

As an extension activity children could create something to stop the slushy drink melting. Perhaps a cup holder made from an insulating material?

More edible experiments

These kitchen science experiments aren't all edible, but brilliant fun all the same!

Lemon Lime Adventures has a brilliant activity for learning about rock layers.

A science bake off would be a great family competition or school science challenge!

If you need even more inspiration I'd love you to check out my book, Snackable Science which contains 60 edible experiments and tests!

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The infamous Skittles experiment is easy, low-cost, and provides lots of investigative opportunities. After trying with warm water, one idea is to use cold water, vinegar or fizzy drink to see if the final result is different.

The Skittles experiment is definitely a must-try science investigation for kids of all ages. It never gets any less impressive and is a great icebreaker activity or simple STEM Challenge.

Colourful Skittles Experiment

What you need:

A plate or container - preferably white

Skittles ( other coated sweets work, too )

Water - warm and cold

Skittles Experiment Instructions

Place the Skittles or sweets into a white container and try to alternate the colours.

Carefully pour water into the container; if the skittles move, quickly push them back into place.

Watch what happens.

Experiment with different shapes and patterns of Skittles.

Why do the Skittle colours spread?

Skittles are coated in food colouring and sugar. When you pour water over the Skittles, the coloured coating dissolves, spreading through the water.

The colour and sugar dissolve into the water and then diffuse through it, making the water the colour of the sweet.

Skittle Experiment Extension Ideas

Time how long it takes the colours to reach the centre of the plate using cold and warm water.

Experiment with different clear liquids such as lemonade and vinegar.

Try using other sweets. Can you find any that work as well as Skittles?

Questions to ask and think about

Why do you think the colours don't mix?

Can you spot the 'S' from the Skittles? What happens to it?

How can you speed up the reaction?

Do the colours mix eventually?

More science investigations using candy

Use any spare Skittles to try some candy chromatography! Did you know that some Skittles contain more than one colour?

If you liked this activity, you'll love my other candy science experiments!

How about one of my easy Roald Dahl themed activity ideas? Make potions for George, chocolate play dough for Charlie, a wormery for The Twits, an upside down house and lots more!

Playdough to Plato has a brilliant growing a gummy bear activity too. Who wouldn't want a bigger gummy bear? Do you think it will taste as good as a small one?

If your children enjoyed this Skittles experiment, they'll love my book, Snackable Science!

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Our next Easter STEM challenge is to build a harness to safely transport a small egg down a zip wire. Once you've built a suitable harness for a chocolate egg, you could try a real egg ( maybe boil it first ) and test to see if the harness works for that as well.

We've got plenty of other Easter STEM Challenges to keep you busy too including eggy toothpick towers, magnet-powered egg cars and lots more easy STEM for kids.

Chocolate EGG STEM Challenge

What you'll need to make an egg zip wire

String, wire or wool

Pipe cleaners and straws

Plastic eggs/chocolate eggs/eggs

Timer

Egg Zip Line Method

This is another great activity for learning about setting up an investigation as a fair test.

Easter STEM Challenge - variables 

Type of zip wire

The incline of the zip wire

Weight of egg

Type of harness

To test one variable, all the others must remain the same each time you test. For example, to investigate whether the weight of the egg changes how long it takes to travel down the zip wire, keep the type of wire, incline and harness exactly the same and change ONLY the weight of the egg. We usually repeat each test 3 times and calculate the average time.

Once you've identified the variables, choose one to test. If you want to investigate how the material the zip wire is made from affects the speed the egg travels down the wire, you'll need to use the same harness, same egg and have the zip wire at the same incline when you test each type of zip wire.

Things to think about

Friction - we found our egg took longer to travel down a zip wire made with rough string than smooth wire, this is because there was more friction between the rough string and harness than smooth string and harness.

More Easter STEM Challenges

Try a harness made using a segment of straw running over the zip wire. The inside of a straw is smooth meaning there shouldn't be much friction between the straw and the wire.

More Friction Investigations

Try this easy slipping and sliding activity as a simple introduction to the concept of friction.

Try these easy force investigations including friction, air resistance and gravity.

More Easter Experiments for Kids

As well as Easter experiments we've also got some fun eggy experiments for kids too!

Buy our NEW book!

Did you know I have several science books available? Rocket Science is full of easy and exciting space-themed activities perfect for kids of all ages, and Snackable Science has 60 exciting edible tests and experiments.

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How many times have you dropped a piece of toast and found it landed butter side down, leaving a smear of butter on the floor?

Is it just bad luck or is there a reason the toast lands that way?

Why does toast land butter side down?

One theory as to why toast lands butter side down is that the toast drops at an angle from the counter or your hands and only has time to rotate half a turn before landing, meaning it lands upside down from it's starting point!!

Investigate

One way to test the theory is to drop three pieces of toast and watch what happens ( place a clean mat on the floor so you can still eat the toast).

Try dropping the toast from higher up, this should change the results as the toast has further to rotate.

Experiment with different thickness and types of bread.

This activity is taken from Snackable Science which contains SIXTY fun and easy edible experiments and investigation you can eat!

More Kitchen Science for Kids

Find out how to make meringue from egg white!

Did you know you can bake ice cream without it melting, using a little kitchen science trick.

Discover how to make an egg float.

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The kitchen is a great place to explore science with children. Even something as simple as melting chocolate is a great science experiment. You can cook, bake, set up a sensory activity, create science magic, make lava lamps and volcanoes, or even play with ice. The creative opportunities with this collection of kitchen science experiments are endless!

The best thing about science in the kitchen is that you probably already have everything you need!

Kitchen Science Experiments for Kids

Egg Experiments

There are so many different things you can do with eggs. Learn about strong shapes, dissolve the shell in vinegar, transform egg white into meringue and make an egg float with these awesome egg experiments.

Kitchen Science for Preschoolers

My preschooler loves gloop or oobleck; if you've never made it before, you must try it. The cornflour ( cornstarch ) and water mixture feels solid if you squeeze it but turns into a liquid when the pressure is released.

Use eggs to learn about tooth decay.

This density experiment will impress everyone. Finding a small object to balance on each layer is an extra fun challenge.

Sweet Treats

Create a Bake Off worthy masterpiece with the Science Sparks Bake off! Find out why honeycomb has bubbles, why cakes turn brown and more!

Can you believe meringue is made from sugar and egg white? Little scientists can transform egg white into a lovely sweet treat.

Discover the power of baking soda by making pancakes!

Making treacle toffee is a great activity for learning about changes of state as the sugar melts and then becomes solid again. Be very careful with the hot mixture, though.

Try some colour mixing with jelly. This is great fun, and you end up with a fun dessert after the investigation.

Grow some sugar crystals and make a lolly.

Find out why popping candy pops or try one of these other candy experiments kids will love!

Savoury Kitchen Science

Make a pizza to learn about respiration and yeast. Breadmaking is another fun activity to see yeast in action.

Make a baked Alaska to find out how to put ice cream in the oven without it melting.

Make some yummy honeycomb and discover why it has holes.

Can you make your butter from cream?

This activity is excellent for learning about colloids. It takes a bit of time and some energy, but the end result is worth it.

Food and Diet Activities

Find out about food groups with this fun activity.

Discover how much sugar common drinks contain.

We've also recently used hula hoops to group foods into healthy and unhealthy.

Milk Based Experiments

Do you know why milk curdles?

Did you know you can make glue from milk which actually sticks!!

This one is not so appetising, but still fun. Find out why apples rot.

Using kitchen equipment

Get imaginative with some candy mixtures

Pull out the kitchen scales and try some weighing and measuring.

More scientific principles

Sugar cubes and absorption

Explore absorption with sugar cubes and coloured water; this is a great way to learn about the properties of materials in the kitchen!

Filter water

Learn about filtering by cleaning up dirty water with a filter.

Make a firework in a glass to discover why oil and water don't mix.

Make an indicator with red cabbage.

Create a pretty milk display to learn about emulsions.

Discover how to make a lemon sink

Chemical Reactions

Dancing raisins

Can you make raisins dance? It might be easier than you think!

Fizzing baking soda rocks

These fizzing rocks are a big favourite in our house. You could even add some plastic bugs to give an added twist.

Blow up a balloon with yeast.

Explore yeast and respiration by blowing up a balloon. Other things to try include baking soda and vinegar, or even popping candy and water!

You could also learn how to blow up a balloon with lemon juice.

Baking Soda Volcano

Finally, how about our old favourite, the infamous baking soda volcano?

What do you think? Can you think of any more kitchen science experiments for us?

Kitchen Science Challenge

Can you assemble a whole meal demonstrating a different science concept with every course?

Snackable Science

I've mentioned it a few times, but did you know I have a new book? Snackable Science is jam-packed full of exciting edible experiments for kids of all ages!

I'm so pleased with how it turned out, so I hope you enjoy reading it as much as I enjoyed writing it.

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This fun tooth decay experiment with egg shells is all about teeth and how to keep them healthy. First, we discussed the importance of brushing teeth every day, and then we chatted about foods that are good for your teeth and those that aren't.

Sugary, sticky foods are not good for teeth as they stick to the surface. Bacteria then break down the sugar to produce acid, which can damage teeth.

Did you know that eating cheese at the end of a meal can help neutralise the acids in your mouth and reduce the chance of tooth decay?

Tooth Decay Demonstration

We used a mouth model and play dough to demonstrate plaque building up on teeth. The giant teeth made a great prop and really kept the children engaged for a long time.

Then we made models of our mouth using more play dough, talking about the size and shape of teeth in our jaw.

Tooth decay experiment with egg shells

We can't experiment on our own teeth, so we are using eggs to represent them, as the shell of an egg is made of a similar substance to tooth enamel!

What you'll need for a tooth decay experiment:

Eggs

Jars

Water

Tea/Coffee

Fizzy flavoured drink

Vinegar

Toothpaste

Instructions

• Pour the same amount of fizzy drink, vinegar, water and tea or coffee into your jars.
• Add a whole raw egg still in its shell to each. Cover an extra egg with toothpaste and also place it in tea or coffee.
• Leave for approximately three days.
• Remove the eggs.
• Rinse the egg that has been kept in vinegar and rub it gently until the shell comes away.

Results of our tooth decay experiment with egg shells

You should see staining on both the fizzy drink and the tea/coffee egg.

We found our toothpaste covered egg stained less than the non toothpaste covered egg.

The vinegar completely dissolved the eggshell, leaving just the membrane behind.

Why do teeth stain?

Tea is rich in tannins, which stain teeth if they're not cleaned properly, while cola and fizzy drinks are acidic as well as containing staining products.

Vinegar ( which is acidic)  dissolves the calcium carbonate in the shell, leaving just the membrane intact. This very cool egg experiment lets you bounce an egg without it breaking!

More egg experiments for kids

Did you know you can make a strong bridge from eggshells?

Walk on raw eggs like Housing a Forest.

Make a model mouth using biscuits, marshmallows, jam and peanut butter. This disgusting activity is one of 60 Gross Science Experiments you can find in my latest book, GROSS SCIENCE.

Or, how about trying one of my other very eggy experiments!!

Extra background information for KS1 and KS2 Science

Teeth are not just for eating, animals often use them to defend themselves or to attack other animals.

Different shaped teeth have different purposes. Flat molars like humans have are for grinding and chewing food, while sharp canine teeth are for tearing food apart ( these are found in carnivores ) and large incisors for cutting and chopping grass ( found in herbivores ).

Caring for teeth 

Cleaning teeth, using floss and mouthwash help keep teeth and gums free from plaque. Plaque is formed by bacteria feeding on the sugar left on the surface of teeth after eating.

Suitable for Early Years Foundation Stage

Physical Development → Health and self-care → ELG

• Children know the importance for good health of physical exercise, and a healthy diet, and talk about ways to keep healthy and safe. They manage their own basic hygiene and personal needs successfully, including dressing and going to the toilet independently.

Key Stage 2 - teeth test

Describe the importance for humans of exercise, eating the right amounts of different types of food, and hygiene.

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One of the easiest ( and tastiest ) ways to introduce science at home is in the kitchen. If you're a regular reader, you've probably already seen my huge kitchen science experiment round-up post, full of simple, tasty, and educational ideas for science in the kitchen. Pancakes are a great way to learn about how changing the ingredients of a dish even slightly can impact the final product in a big way.

To get the perfect pancake for your taste, you need to get the ingredients right. If you like big fluffy pancakes, you'll need baking powder to add bubbles. If you're more of a crepe person, skip the baking powder.

Pancake Science Experiment

What you need

We used the recipe below for the pancake batter, but you can use any mixture you want.

• Two eggs
• 300ml milk
• 100g plain flour
• Baking powder
• One tablespoon sunflower oil or butter
• Egg whites whisked

Instructions

Sift the flour and whisk the egg into it with a splash of milk. Add the oil or melted butter, and whisk in the rest of the milk. 

Keep the whisked egg whites to one side.

We tested four different mixtures, but you can adjust the variations however you want, just keep the basic mix the same.

• Basic pancake mixture.
• Basic pancake mixture with a teaspoon of baking powder.
• Basic pancake mixture with some whisked egg white.
• Basic pancake mixture with baking powder and whisked egg white.

Pancake Experiment Questions

How will the baking soda and whisked egg affect the pancake?

The baking powder and egg white should add air to the mixture, giving it more volume than the basic mixture.

How would you expect the pancakes made using different mixtures to differ?

We would expect the pancakes to vary in size. The smallest should be the basic mixture, and the largest should be the mixture of baking soda and whisked egg white.

Results

Pancake Science - the perfect pancake

Baking powder acts as a leavening agent, which means it adds bubbles of gas ( carbon dioxide ) to the dough. This chemical reaction happens when the baking powder is mixed with the moist dough.

The starch in the flour mixes with the water in the dough mixture to form a gluten matrix which then sets, leaving the holes left by the gas bubbles inside. If you don't use baking powder in a pancake, it will be much flatter.

Baking powder is an example of a chemical leavener. An example of a biological leavener is yeast.

Egg whites are another way to add air to the pancake mixture. When whisked, the egg whites trap air, increasing their volume. When carefully mixed into the pancake mixture, the air is also added.

Did you know that citric acid  (found in lemon juice) stimulates your taste buds? Try adding some to your pancake.

These photos were taken with a microscope. The air bubbles in the mixture with baking powder are clearly visible.

More pancake science experiments

Find the best syrup for your pancakes with a viscosity syrup race!

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Fresh eggs sink, and older eggs float. Eggs have air cell that becomes bigger as they age. Once the air pocket is big enough to make the egg less dense than water, the egg floats!!

Another way to make an egg float is to increase the density of the water the egg is in! Once the water becomes denser than the egg, the egg will float. We can increase the density of water with salt.

This easy kitchen science experiment just needs salt, water and a container.

How to make an egg float

You'll need

• A bowl or large glass
• Tap water
• Table salt
• Fresh Egg

Instructions

• Fill the bowl or glass about ⅔ full with tap water.
• Drop the egg carefully into the bowl and watch as it sinks to the bottom.
• Remove the egg and add salt to the water stirring continuously. Keep adding salt until the egg floats.

Why does an egg float in salty water?

Objects sink when they are more dense than water and float if they are less dense than water.

Adding salt increases the density of the water.

Once the water is more dense than the egg, the egg floats.

You could also try other objects to see what else you can make float. Just remember to check the object sinks in tap water first. Why not try one of my other sink or float experiments?

More Kitchen Science Experiments for Kids

Find out how to make an egg bounce.

Discover how to bake ice cream in an oven without it melting.

Learn about the Maillard reaction, find out what a leavening agent is and more science in the kitchen with a science bake off!

Find out why honeycomb is bubbly.

Rainy Day Mum uses honeycomb to talk about igneous rocks!

I also have a HUGE collection of kitchen science experiments that will keep you busy for months!

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Eggs with no shells are definitely one of the things my children find most intriguing. I've made bouncy eggs for nursery children to look at and for secondary school children to use as part of an osmosis experiment.

This fun bouncy egg experiment is great fun for kids of all ages and fascinating for adults too!

I also have a huge collection of egg experiments you might like.

Bouncy Egg Experiment

What happens to an egg when you drop it? It smashes.

So how can you make an egg bounce?

How to make an egg bounce

Place an unboiled egg in a container of vinegar for about 24 hours. The vinegar should completely cover the egg. If you want to remove the shell faster, take it out of the vinegar every couple of hours and rinse the egg under cold water while gently rubbing away the shell.

Once the whole shell has dissolved, you have a naked egg which should bounce. Some eggs seem to break more easily than others, so you could try experimenting with different kinds of eggs to see if a certain type or size makes a difference.

To bounce your egg, drop carefully from a low height, the egg should bounce up from the surface. Can you measure at what height it breaks? Or try bouncing on different surfaces?

How about drawing a table to demonstrate your results?

If you don't want to break the eggs, how about shrinking an egg ?This is a fantastic way to learn about osmosis.

More Egg Experiments

Use eggs to learn about tooth decay!

Find out why an egg can seem to be unbreakable.

Make an egg shell bridge.

Key Stage 1 Science

Investigative skills

Ask the child to predict if an egg can bounce using past experience of the properties of the shell.

Obtain and present evidence

Did you draw a table to demonstrate how high the egg bounced?

Consider and evaluate evidence evidence

Were the results as expected?

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This egg experiment looks at how something we think of as being brittle and weak can actually hold a heavy load under certain conditions. We're going to investigate how strong an eggshell is by using half shells to make a bridge.

How strong is an eggshell?

You'll need

• at least four eggs ( we broke a few making the domes )
• a pen
• scissors or a sharp knife
• heavy books

How to make an eggshell bridge

• Tap the end of an egg gently on a hard surface to break it. Empty out the contents ( maybe use it to make scrambled eggs? ) and rinse the inside of the shell. You'll need four eggshells (so probably more than four eggs, as the domes can be tricky to make).  Take a moment to think how brittle and easy to break the eggshell is.

Method 1

• Draw a line around the egg as evenly as possible, then using the line as a guide, carefully score the shell. Ask an adult to do this.  It is worth spending a lot of time on this step, as we have found it frustratingly difficult.  Ensure the scoring is continuous and completely encircles the egg.

Method 2 - the easiest

• Very carefully break off pieces of shell up to around the centre point.  You need four half eggshells of the same height.  Scissors sometimes work, too.

• Place the four shells in a rectangle shape, and slowly place books on top. See how many books you can add before the eggshells crack.

Image taken from Snackable Science

How strong is an eggshell?

Some shapes are stronger than others.  Eggs which seem fragile are actually very strong in certain ways (try crushing an egg by squeezing the ends between your hands (maybe over a sink or outside!).

Eggshells naturally form a dome shape.  Domes are very good at spreading weight evenly in all directions so that no part of the dome has to support more weight than another part.  The downward force of the weight of the books is transferred evenly by the dome shape down to the hard surface

Think more: What other shapes are strong? Where can you see these shapes in buildings or nature?

Starter: Have a look at bridges.

Try our investigation using paper to find out about strong shapes.

More Science for Kids

Make an unbreakable egg or try one of my other easy egg experiments for kids, including making a naked egg, a bouncy egg and a Humpty Dumpty egg drop.

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This collection of Humpty Dumpty science experiments is perfect for Early Years Science to fit in with a Nursery Rhyme theme. Older children could use it for practising designing an experiment following correct scientific procedures. I've used plastic sealable bags to keep the mess contained, but children could also wrap the egg in protective materials ( not the cous cous or rice ) and use masking tape to keep it all together

Humpty Dumpty sat on a wall

Humpty Dumpty had a great fall

Print the experiment instructions

Humpty Dumpty Egg Drop Experiment

Younger children will love testing to see if their egg has broken in this super simple activity. Just place a boiled egg into sealable plastic bags filled with different items to cushion the fall and see which protects the egg the best.

Materials for Humpty's egg drop experiment

Boiled eggs

Ziploc bags

Materials to test - cotton wool, cous cous, rice, bubble wrap.

Points to consider

What variables do you need to keep constant to make the experiment as accurate as possible?

Variables to keep constant

• Height to drop the egg
• Force at which to drop the egg - we used the same person to hold the bag as high as they could and then drop it without using any added force. This meant the height and force should be the same for each egg.
• Amount of material to test - this is a tricky one. We drew a line on the bag and filled it to the same height with each material; there are some issues with this, as the bubble wrap had more air gaps than the other two materials.
• Placement of the egg - if the egg was on the bottom of the bag, it wouldn't be cushioned, so we tried to make sure the egg was in the middle of the material we were testing.
• The surface on which to drop the egg - this should be the same

Variable to change

The material used to cushion the egg.

Humpty's egg drop instructions

Place your material to test in a sealable plastic bag, add the egg and make sure it's completely covered by the test material.

Hold the bag at the top as high as you can and drop the bag.

Check the egg for damage.

Repeat for each material. If the egg cracks, use a new egg for the next test.

Extension Humpty Dumpty Science Ideas

Can you try the experiment by dropping the egg onto different surfaces or from a greater height?

What other materials could you test?

More Humpty Dumpty Science Ideas

Build Humpty Dumpty a Wall

Can you build and test a wall for Humpty Dumpty?

Materials to test

Sugar cubes

LEGO

Sweet and candy

How to build a wall for Humpty Dumpty

Build a wall and test it by rolling a marble towards it.

Remember to make each wall the same size and use the same marble and the amount of force behind the marble when you roll.

Can you use something to stick your wall together?

Can you tell the difference between a raw and a boiled egg?

Hint - try spinning the eggs.

How strong is Humpty Dumpty?

Stick a cardboard Humpty Dumpty to a wall using different materials, for example, blu tack, velcro etc. and see which holds him in place most securely.

More Nursery Rhyme Activities for Kids

If Nursery Rhyme crafts are more your thing, check out this amazing selection from Red Ted Art.

Make an umbrella for Incy Wincy Spider and test to see if it keeps the spider dry.

Or how about one of my other egg experiments.

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This is a great Christmas science activity or for World Book Day to sit alongside reading The Gingerbread Man or Hansel and Gretel.

It's also a brilliant Christmas baking STEM challenge! Challenge your friends to make a house and test to see whose is the strongest!

If you don't fancy baking the gingerbread an easier idea is to use square ready-made biscuits or crackers in a tent shape like the image below.

Ask children to make predictions drawing on existing knowledge as to which substance will hold the house together most effectively.

This is also a great activity for practising designing a fair test and carrying out correct experimental procedures.

How to make a Gingerbread House

Gingerbread House

Gingerbread pieces

Icing sugar/marshmallow fluff / royal icing / liquid glucose

Sweets

Investigation Instructions

The easiest way to do this is to bake a thin sheet of gingerbread and use cutters to cut it immediately after taking it out of the oven. This ensures all the pieces are exactly the same size.

We used two squares and two smaller rectangles, but you could use any shape you wanted.

Build a gingerbread house for each type of sticky substance you are testing. Try to use a similar amount for each wall on each house.

Leave overnight to harden.

Image taken from Snackable Science

Factors to keep constant

Size of gingerbread pieces

Amount of sticky substance used

Time left to harden

Type of sticky substance

How to test for strength

Pick up the house and see if it stays intact.

Roll a marble or small ball at the house. Does it fall over?

Suitable for Key Stage 1 Science

Using observations to suggest answers to questions

Performing simple tests

Using scientific language to answer a question describing how to carry out a fair test.

If you don't want to bake, try using three rectangular biscuits. You could even give them to friends as gifts. 

Biscuit houses inspired by the lovely Red Ted Art.

More Science for Kids

If you liked this idea I have LOTS more kitchen science experiments to share.

You might also like my Kitchen Science Bake OFF!!

Another idea is to add some edible glass to your gingerbread house. The easiest way to do this is to cut out a window shape before baking and place a clear mint or two inside. The mint will melt and look like a window!

Images are taken from Snackable Science which is full of awesome edible experiments for kids!

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What is a Mixture?

A mixture is a substance in which two or more substances are mixed but not chemically joined together, meaning that a chemical reaction has not taken place.

Mixtures can be easily separated and the substances in the mixture keep their original properties.

Imagine mixing skittles and full size marshmallows, the individual components (skittles and marshmallows) could easily be separated using a filter and each component of the mixture ( skittles and marshmallow ) doesn't change. 

How to make a mixture

You can make your own mixtures with items from around the house.

1. Firstly try to make a mixture of toys.

2. This time use cereals or sweets.

What is a solution?

A solution is made when a solid (which we call a solute) dissolves into a liquid (that we call the solvent) One example of a solution is salt dissolved in water. The salt and water can be separated again by evaporation ( the water will evaporate if left in a hot place leaving he salt behind ).

Investigation

Aim: To test out these three mixtures to see which form solutions and which don't

• Salt and Water
• Sugar and Water
• Sand and Water

Results Table

You should find that both salt and water and sugar and water dissolve and form solutions and that sand sinks to bottom!

How do you separate mixtures?

Can you separate the components out of the mixture again? Hint - to separate the sand from water you could use a sieve. This is possible as the sand is insoluble ( doesn't dissolve in water ).

Salt and sugar are soluble ( dissolve in water ) and can be separated by evaporation.

Another way to separate a mixture is by using a process called chromatography.

Challenge - how would you separate rock salt and water?

Rock salt is a mixture of salt and sand and is often spread on roads in winter to stop cars skidding.

Stage 1 - Grinding

First the rock salt should be ground using a pestle and mortar.

Stage 2- Dissolving

The ground rock salt should be dissolved in a beaker and stirred thoroughly.

Stage 3 - Filtering

The solution of water and rock salt should be passed through the filter paper where the sand ( which will not have dissolved in the water ) will collect.

Salt does dissolve in water and so will pass through the filter paper.

Stage 4 - Evaporating

To separate the salt from the water the water needs to be evaporated off, either by leaving the salty solution in the sunshine or placing under a heat source.

The salt will form as crystals - this process is called crystallisation.

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Did you know you can bake ice cream without it melting? A Baked Alaska is a dessert with a sponge cake base, ice cream middle and meringue top!

The secret to keeping the ice cream cold is all in the meringue! Meringue is full of air bubbles which stop the heat from the oven reaching the ice cream! The meringue ( and sponge cake base ) act as insulators trapping the heat and stopping it melting the cold ice cream!

This activity is taken from Snackable Science which contains 60 exciting edible experiments and is available from Amazon NOW!

Ingredients for Baked Alaska

Ready made sponge cake
Jam
Vanilla ice cream
3 egg whites
175g caster sugar
½ tea spoon cream of tartar

How to make Baked Alaska

Preheat the oven to 200 °C.

Slice the cake so you have five 1cm thick slices and place each on a baking sheet. Spread a thin layer of jam on top of each slice.

To make the meringue whisk the egg whites until they form stiff peaks, slowly add half the sugar and cream of tartar and whisk again.

Add the rest of the sugar and whisk again until the meringue looks thick and glossy.

Place a scoop of ice cream on top of each sponge cake slice and cover with meringue mixture.

Bake for 3-4 minutes and serve immediately!

You managed to bake ice cream without it melting!

Download the Baked Alaska Instructions here:

More Kitchen Science for Kids

Discover the science behind meringue and build meringue towers.

Try some candy chromatography and find the hidden colours in sweets.

Make ice cream in a bag using the super cooling power of salt.

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When making some jelly last week, I noticed the packet said it wouldn't set if pineapple, kiwi or papaya were added to it. We decided to find out why pineapple stops jelly setting.

If you love science in the kitchen don't forget we've also got 50 fun kitchen science experiments and ideas for a science bake off!

What you need

• Jelly cubes
• Fresh pineapple
• Tinned pineapple
• Any other fruits you wish to test
• Small bowls

Jelly and pineapple investigation instructions

• Make the jelly up as per the instructions.
• Divide into several small bowls.
• Add a different fruit to each bowl.
• Leave one just as jelly - this is our control

What happened when we tested jelly and pineapple?

We found only the jelly containing the fresh pineapple did not set. In one bowl I had just two small pieces of pineapple, this was enough to stop it setting.

Why does pineapple stop jelly setting?

Jelly contains gelatine which partially consists of protein molecules. It sets because the protein molecules tangle up as they cool down trapping the water to make a solid. Fresh fruits such a pineapple, kiwi and papaya contain enzymes which break down these protein molecules, making them smaller, so they can't tangle up, which stops the jelly setting. This is similar to how the enzymes in your stomach break down food.

The tinned pineapple jelly set because as part of the tinning process the pineapple has been heated  to destroy  bacteria. This process has also  destroyed the enzymes ( they are denatured ).

The enzyme in pineapple is called bromelain and the one in kiwi actinidin.

Why does jelly set?

Jelly contains gelatin, which is a processed form of collagen. Collagen is the most common protein found in humans and other mammals. When the gelatin is dissolved in hot water the bonds holding the collagen protein together are broken.

As the gelatin cools new bonds form trapping the water between them.

Why does jelly wobble?

The liquid in the jelly is trapped between gelatin bonds which is why it wobbles!!

What is bromelain?

Bromelain is a protein-digesting enzyme mixture found in the stem, fruit, and juice of the pineapple plant.

Bromelain has also been used to medicinally for centuries as it has anti inflammatory properties.

More Kitchen Science for Kids

Find out how to make meringue and then make cream and strawberry meringue towers! Which will topple first?

Try one of our delicious candy science experiments including candy towers, candy chromatography and an edible DNA model.

Did you know you can make butter from cream?

Or, how about homemade ice cream using the super cooling power of ice and salt!

If you liked these activities you'll love my new book Snackable Science. It contains 60 exciting edible experiments for kids of all ages, including cell cupcakes, honeycomb, a fudge model of the earth and lots more delicious science for kids!

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We've got some easy ( and tasty ) earthquake experiments to share today! Did you know the Earth is made up of large pieces of rock called tectonic plates? Where two tectonic plates meet is called a fault. If two plates rub together at a fault waves of energy ( seismic waves ) come to the surface of the Earth which are felt as an Earthquake.

Earthquakes can be different magnitudes, sometimes they are just a small tremor and other times cause huge amounts of damage to the land above. An earthquake of magnitude 3 would be very small, 6 would cause substantial damage and 9 would have catastrophic effects.

The amount of damage an earthquake causes is measured by the Mercalli Scale, which is a measure of intensity.  This changes depending on the part of the Earthquake being measured. For example damage at the epicentre of an Earthquake would be more than further away from the epicentre.

If an Earthquake happens at the bottom of the sea it can push water upwards creating huge waves called tsunamis.

Earth like a Peach

Imagine the Earth as being like a peach made up of layers. The stone in the middle is the core, while the fleshy part is like the Earth's mantle which contains magma and the skin is like the crust.

Another way to picture this is to make a model of the Earth like this one we made with playdough.

Good Foundations - Earthquake Experiment

You'll need:

Jelly

Chocolate brownie or other foundation

Gummy sweets

Cocktail sticks

Earthquake Experiment Instructions

Make jelly and a brownie or other foundation layer to test in a tray or on a plate. If you don't want to use food items, play dough, clay etc would all work well too.

Build a tower using the cocktail sticks and jelly sweets. Ours looked like this.

We tested our tower on it's own and then in jelly, flapjack and brownie by counting the number of shakes needed to make it fall over and recorded our observations.

Images taken from Snackable Science

Earthquake Experiment - Make it fair

The same person shook all our towers, so we could try to make sure the same force was used each time.

We used a tower of the same height and using the same number of sweets/toothpicks each time.

Keep the depth of the foundations the same.

Extension ideas

What happens if you build a taller tower?

What other foundations could you use?

Can you think of a way to strengthen your tower?

Snackable Science

This activity can also be found in my latest book, Snackable Science

Earthquake Facts for Kids

A seismometer is used to measure the magnitude of an earthquake. Earthquakes are measured on the Richter Scale.

Movement of a tectonic plate of just 20cm is enough to set off an earthquake!

Small earthquakes can be felt as a slight tremor, but larger earthquakes can cause severe damage, making buildings collapse, causing landslides, flooding and explosions. 

More Earthquake Science for Kids

Make your own Seismometer - this is super easy and great fun to engineer.

Find out about plate tectonics with an orange!

Scientific American have a brilliant LEGO based earthquake activity too!

Suitable for  – Key Stage 2 – Human and physical geography.

Key Stage 2 - Science

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Did you know you can use chromatography to separate the different colours in the coating of colourful candy? This fun science experiment is perfect for learning about separating mixtures and can even be used as a science and art activity too!

This activity can also be found in my new book Snackable Science. If you click the image below you can download the instructions from the book in printable form! Hopefully it gives you a feel of what the book is like. There are 59 other edible activities to try, so plenty to keep everyone busy ( and well fed ) for a long time!

What is Chromatography?

Chromatography is a technique used to separate mixtures. The mixture is passed through another substance, in this case filter paper. The different colour ink particles travel at different speeds through the filter paper allowing us to see the constituent colours of the pen ink.

What you need for candy chromatography

M & Ms, Skittles or other coloured candy

Water

Pipette (UK : http://amzn.to/2wavyHO US: http://amzn.to/2eYqSkY )

Tray or plate

Water

Filter paper cut into strips. ( UK: http://amzn.to/2vivaKZ US: http://amzn.to/2hdA6ur )

Test tubes or thin beakers ( UK: http://amzn.to/2vUIItr US: http://amzn.to/2eXLVV7 )

Paper clips

Chromatography Instructions

Place the candy onto a plate. It's a good idea to use different colour sweets, so you can easily compare the results.

Carefully use a pipette to drop water onto the sweets and leave for a few minutes, until colour from the sweets dissolves into the water.

Use a pipette to suck up the coloured water and carefully drop onto the bottom of a strip of filter paper.

Use one strip for each colour of sweet.

Thread a paper clip through the filter papers and leave to rest in a test tube of water with just the bottom of the paper in the water,

Leave for about 10 minutes and observe what happens.

The filter paper shows different colour bands because the colouring on the candy shells is a mixture of colours. The colours that travel furthest up the filter paper are the most soluble!

Can you guess which filter paper was  a green sweet?

Chromatography Extension Ideas

Try to separate felt tip pen colours. Investigate to discover whether you get the same results as with candy for each colour? For example, are the colours in a green Skittle and a green M&M the same?

If you enjoyed this investigation why not try our other exciting candy science ideas too.

How are mixtures separated?

Mixtures can be separated in lots of different ways, I've listed a few below.

• Mixtures with a solid suspended in a liquid can be separated by filtering. Try experimenting with a paper towel filter or sand and stone filter.
• Decanting is where a liquid is separated from a solid which has settled by pouring the liquid carefully out of the container leaving the solid behind.
• Centrifugation is where a substance is spun very quickly forcing the heavier particles to the bottom.
• Distillation is a process where mixtures are separated by heating. The vapour of the liquid with the lowest boiling point is released first. The vapours can then be condensed using something called a Liebig condenser.

More Chromatography Investigations

Add a bit of science to phonics learning with this fun chromatography and phonics activity.

Try some art and science with these chromatography butterflies

This activity is also found in Snackable Science!

Image credit below - Snackable Science

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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.

The post What is the Maillard Reaction? appeared first on Science Experiments for Kids.

I've lost count of the number of water science experiments we've done over the years. Water is pretty amazing. Did you know it is the only natural substance to exist in three physical states at temperatures naturally occurring on Earth?

Facts about Water

• Water covers about 70% of the surface of the Earth.
• Water expands when it freezes.
• We need water to survive.
• Water expands when it freezes.
• Water can move upwards!!

Water has lots of properties that make it just brilliant for simple science investigations!

Water Science Experiments and Investigations

Freezing and Melting Investigations

Freezing and melting investigations are always fun. For younger children, let them play with ice cubes while they melt. You can freeze small toys inside to make this a bit more exciting.

We had great fun with our LEGO ice excavations recently, but you can also freeze superheroes, bugs or anything else that might spark an extra interest.

Just getting the child to recognise that the ice is cold and how that feels on their fingers is a great sensory experience. Remember to let the ice melt a little first, as ice can be sticky when first removed from a freezer.

Water Cycle Experiments

Make a mini water cycle or a water cycle in a bag. These are great science activities for older children and help explain a tricky concept.

Water and Density

Density is a tough concept to grasp, but hopefully, this density science trick is interesting and simple enough to help it all make sense. Salt increases the density of water, so the coloured salty water doesn't mix with the less dense water on top!

Density jars are also great fun. Children can try and find different small objects to float on the layers. These can be very simple and just contain water and oil, or children can experiment with layers of washing up liquid (dish soap ), treacle, honey and other non-toxic liquids.

Transport of Water in Plants

Learn about transpiration and make some pretty coloured flowers. I love this activity. If it works well, you can see the path the water takes to reach the edge of the petals.

Sinking and Floating Experiments

How about some simple sinking and floating experiments? This is great for young children, who love to watch objects sink and float. Older children can make a plasticine boat and discover whether an item that previously sank can float in the boat. Or, try and predict which objects will sink and which will float.

Did you know you can use a bit of clever density science to make an egg float?

Children can also make a lemon sink if they understand why it floats in the first place!

Oil and Water Experiments

Find out why oil and water don't mix. We've also demonstrated this using coloured water and pipettes, which was brilliant fun.

Osmosis Experiments

Learn about osmosis ( water passing through a semi-permeable membrane ) using eggs. The term osmosis might sound complicated, but this egg demonstration makes it more understandable, and don't worry if your children don't understand straight away or are too young. It's still fun to watch the eggs expand and then shrink.

Absorbing Water

How about exploring absorption using sugar cubes? The fact that you can watch the water rise up the cube is brilliant and appeals to children of all ages.

A walking water investigation is another excellent way to learn about how water is absorbed by different materials.

Water Powered Rocket

Learn about air pressure with this very cool water-powered bottle rocket.

Filtering Water

Discover how to clean water with this easy filtering activity using paper towels or using sand and stones.

Another idea is to investigate how to clean up water after an oil spill.

Is it waterproof

Investigate which materials are waterproof by using them as a roof for a LEGO house and investigating whether they keep the floor dry.

Dissolving in Water

Predict and test which substances will dissolve in water.

Do you have any more water science experiment ideas for us?

More Science for Kids

Try my fun science tricks or easy Fairy Tale STEM challenges!

If you enjoyed these experiments, don't forget to check out the rest of my 100s of other science experiments for kids, too!

The post Water Science Experiments for Kids appeared first on Science Experiments for Kids.

Did you know you can make butter from cream? This is a super simple way to make butter at home, but it does require a bit of effort.

You need good quality double cream, a jar and some strong arms!

This activity is a fun kitchen hack if you've got leftover cream and a great way to learn about colloids and emulsions too!

Cream is basically fat droplets mixed in water. When you shake the cream in the jar, the fat droplets stick together to form butter and a milky liquid called buttermilk.

How to make butter from cream at home

You'll need

Double cream - at room temperature

A container with a lid

1-step method of making butter in a jar

Let the cream warm up to room temperature.

Half-fill the jar with the cream and shut the lid tightly.

Shake the jar until you feel a lump form. You do need to shake quite vigorously, so maybe you can round up some friends to help. First, the cream will thicken up a little like whipped cream.

Shake for longer and the cream will turn into a lump of butter with some milky looking liquid left behind. The milky liquid is buttermilk.

Wash your hands and gently squeeze as much buttermilk from the butter as you can. Give it a rinse under the tap and taste it!

What do you think of the taste? It should taste quite different to shop bought butter as it doesn't have any added flavourings or preservatives.

Why can you make butter from cream?

When you think of a mixture of substances what do you think of? Probably not cream? Cream is a type of mixture called a colloid, it is made up of very tiny particles of fat dispersed in water. When you shake the cream the fat particles stick together, forming butter.

Cream and butter are a type of colloid known as an emulsion.

Did you know it was so easy to make butter?

More ideas for science in the kitchen

For more kitchen science ideas, check out my fantastic kitchen science experiments.

As well as making butter from cream, did you know you can make glue from milk?

The post How to make butter from cream appeared first on Science Experiments for Kids.

Did you know you can make homemade ice cream in a bag in less than 10 minutes with just milk, salt and ice? You don't even need a freezer!! Our ice cream recipe is easy for kids to follow and a fun science activity at the same time.

Experiment with different flavours and toppings to find your favourite ice cream dessert!

This awesome kitchen science experiment for kids involves lots of interesting chemistry, is inexpensive and very simple!

What is ice cream?

Ice cream is made up of droplets of fat from milk jumbled up with millions of tiny crystals of ice and pockets of air.

This activity uses the freezing power of salt and ice to create ice crystals in milk without a freezer!

Homemade Ice Cream in a Bag Science Experiment

What you need to make ice cream in a bag

A large bag of ice

Salt

Milk - we used chocolate milk, but any kind of milk or non-dairy drink will work

A tablespoon of sugar and a teaspoon of vanilla essence - optional

Resealable bags

Tea towel

How to make ice cream in a bag

1. Pour a cup of milk into a resealable plastic bag. Add the sugar and vanilla essence ( or just use flavoured milk ). Make sure the bag is properly sealed.
2. Half-fill a bigger sealable bag with ice and add a good amount of salt.
3. Put the milk bag into the ice bag and give it a good shake.
4. Keep the milk in contact with the ice as much as possible.
5. Keep rolling the ice over the milk. The ice in the bag will get VERY cold, so put a towel around the bag to protect your hands.
6. Check the milk after 5 minutes. It should be a similar consistency to ice cream. If not, keep going for a bit longer.

Why does ice cream in a bag work?

Pure water freezes at 0°C. The addition of salt lowers the freezing point by a few degrees ( freezing point depression ). This means when salt is added to the ice in the outer bag, the ice (which is at 0°C) is above its freezing point, so it starts to melt. Melting needs energy, which in this case comes from the milk mixture in the inner bag. Heat energy is absorbed from the milk, making ice crystals form between the tiny fat molecules.

The more salt that is added to the ice, the lower the freezing point. For the ice to melt, heat must be absorbed from the surroundings ( in this case, the milk mixture ), causing it to freeze.

The ice will feel VERY cold, which is why you'll need a towel to cover the bag after a  few minutes.

Extension ideas

Create and test different homemade ice cream recipes.

Place a mixture of ice and salt in a freezer to investigate whether it freezes or not.

This activity would be perfect for a science club or a fun STEM Challenge. You could even have a competition to see who can make the COLDEST ice cream!

More Awesome Kitchen Science for Kids

Make a whole meal of science experiments! This is a great science or cooking challenge for homeschooling or school!

Try one of my other easy kitchen science experiments for kids, including finding out why cakes turn brown in the oven, why pineapple stops jelly setting, building towers with toothpicks in a flapjack or brownie base and lots more!

If your children love edible experiments, you might also like my kitchen science book, Snackable Science, which includes SIXTY fun and easy edible experiments!

Affiliate links

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Did you know you can make an egg drop into a bottle without touching it? This easy egg in a bottle experiment is a great, fun way to demonstrate air pressure.

What is air pressure?

Air pressure is the force exerted by air on any surface in contact with it.

Egg in a bottle experiment

You'll need:

A boiled egg

A clean, dry glass bottle or jar with a neck a little smaller than an egg

Matches - it took us a few attempts to get it to work

Instructions

Place the cooled boiled egg on top of the glass bottle or jar to check there is no way the egg will drop through.

Ask an adult to light a match and drop it inside the jar. Quickly place the egg on the top of the jar.

Watch as the egg drops down inside. Be a little patient with this as the egg doesn't drop down immediately, but should drop slowly once the match goes out.

Why does the egg drop into the bottle?

The matches heat up the air inside the glass jar or bottle.

The warm air expands and some escapes out of the jar.

Once the match goes out, the air starts to cool, and the air pressure drops.

This means the air outside the jar now has a higher pressure than the inside, and forces its way inside the jar, making the egg move downwards at the same time.

Related Posts

More air pressure experiments for kids.

Make an egg shrink, make an unbreakable egg and lots more egg experiments.

The post Egg in a Bottle Experiment appeared first on Science Experiments for Kids.

These red cabbage indicator colour changing potions are fantastic fun for kids of all ages and very easy to create. We used red cabbage indicator and added different amounts of baking soda ( an alkali ) and vinegar ( an acid ) to make the different colours.

What is a pH Indicator?

A pH indicator is a substance which has one colour when added to an acidic solution and a different colour when added to an alkaline solution.

Acids have a low pH and bases a high pH.

Why does red cabbage make a good indicator?

Red cabbage contains a chemical called anthocyanin. This changes colour depending on the acidity of its environment. It turns a pink/red colour in the presence of an acid, is purple when neutral and when added to an alkaline substance turns blue or green.

How to make Colour Changing Potions

Red Cabbage Indicator Ingredients

Red Cabbage ( chopped )

A pan

Water

A stove

Strainer

Selection of jugs, jars and beakers

Vinegar

Dish soap ( washing up liquid )

Instructions

Place your chopped red cabbage into a pan, cover with water and heat until the water turns purple ( ask an adult to help )

Carefully pour the mixture through a strainer to remove the red cabbage and collect the solution in a container.

Pour the indicator into smaller beakers, it doesn't really matter how much you use, but we made ours about half full.

Add different amounts of baking soda or vinegar to each one.

How many different colours can you make?

Colour Changing Potions Challenge

For a little extra fun, you can add vineger to a beaker containing baking soda and vice versa to see a fizzy colour changing reaction.

Safety note

Wear safety goggles if using strong acids/bases.

An adult should help with the chopping and heating of the cabbage.

More Red Cabbage Indicator Ideas

We love how The Science Kiddo froze some red cabbage indicator to test different substances

Make your own pH indicator test strips

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This is a great little science experiment that kids will love! When baking soda and vinegar are added, raisins dance around a glass of water.

Dancing Raisins Experiment

What happens when you put a raisin in a glass of water?

It sinks!

Do you think it's possible to make raisins rise to the top and jump around?

Find out in this simple baking soda science investigation.

What you need:

A pint glass

Warm water

Raisins or anything else you would like to test.

Bicarbonate of Soda (Baking Soda)

White Vinegar

Why do the raisins dance?

The vinegar and bicarbonate of soda react to form carbon dioxide. The carbon dioxide bubbles collect over the surface of the raisins. As carbon dioxide is lighter than water, it rises to the top and takes the raisins with it. As the bubbles pop at the surface the raisins drop again, only to be covered in bubbles again at the bottom until the reaction finishes.

More Investigation Ideas

Try to find the smallest amount of baking soda and vinegar that allows the raisins to dance. Try with just one raisin and then investigate to discover if you need more to make two raisins dance.

Can you think of anything else this would work with? You could investigate using other dried fruits and record how well each dances.

We tried with small LEGO pieces and found that they sank when they filled with water and once the reaction started they jumped to the top, but didn't dance around.

We then tried with small coins, but these didn't move at all, you can see how all the bubbles of carbon dioxide have gathered on the surface though.

Another idea is to attach something to the raisins and see if they still dance.

Why do baking soda and vinegar react?

If you combine an acid ( vinegar ) and an alkali ( baking soda ) they react together to neutralise each other. 

The reaction releases carbon dioxide gas, which is the bubbles you see.

More baking soda experiments for kids

Create a fizzy Monster Tea Party!

Our baking soda powered boat is a fantastic engineering challenge.

Everyone loves a baking soda volcano. We also have a sand volcano, a snow volcano, and a papier-mache volcano.

Or try some fizzing rocks with baking soda, what would you hide inside?

The post Raising Raisins - baking soda investigation appeared first on Science Experiments for Kids.

There are two parts to today's activity. First you're going to discover how meringue is made. Can you believe it starts out as egg whites and sugar?? Do you know why egg yolk isn't used to make meringue just the white?

Once you've made delicious meringue pieces, you're going to build delicious meringue, cream and strawberry towers.

Did you know egg whites are 90% water? and about 10% protein.

Proteins are made up of amino acids. Some amino acids are are attracted to water while others are repelled. When you whisk the egg white mixture you add air to it. The amino acids which are repelled by water attach to the air. The more you whisk or beat the mixture the more amino acid covered bubbles you create, making the mixture fluff up. The sugar acts as a stabiliser helping the amino acids  bond together.

Question: Why don't you use egg yolk in meringue?

Egg yolks contain fat which interferes with how the proteins arrange themselves, stopping the mixture fluffing up.

Meringue Ingredients

4 egg whites

200g caster sugar

Bowl - not plastic as these tend to retain oils which might interfere with the mixture

Electric whisk

Spoon

Parchment paper

How to make Meringue

• Pre-heat the oven to 110 degrees, gas mark 1.
• Line 2 baking sheets with parchment
• Put the egg whites in a bowl and whisk slowly at first then faster as they expand. Once you get stiff peaks the egg whites are ready.

• Add the sugar slowly a few tablespoons at a time and whisk after each sugar addition
• Place 2 heaped tablespoons of mixture onto the baking parchment, leave a gap and then repeat until all your mixture is used up.
• Place in the oven for about an hour and leave to cool.

Meringue Towers

First build towers using just meringue. Look carefully at the shape and size of each one to try to build a stable structure.

Another idea is to use whipped cream and strawberries to stick it together! Can you measure how tall your biggest tower is?

Once you're finished you've got a lovely dessert to eat!

More easy kitchen science for kids

Find out why popping candy pops or build an edible DNA model with this fun collection of candy science experiments.

Learn about changes of state by making your own slushy drinks.

Do you know what causes the Maillard Reaction?

The post Why don't you use egg yolk in meringue? appeared first on Science Experiments for Kids.

Making oobleck, also known as cornflour gloop or slime, was one of the first science activities I wrote about on Science Sparks. It's a brilliant indoor or outdoor science activity that only needs two ingredients, so it is super easy as well! I've given this very old post about how to make oobleck a bit of an update and refresh, so I hope you like it!

What is oobleck?

Gloop or oobleck is just cornflour and water. It's very easy to make and creates a lovely gooey slime that feels solid when you scrunch it up and like a liquid if you let it flow through your fingers.

Oobleck Recipe

• Cornflour
• Water
• Food colouring - optional
• Ice cube trays - optional
• Mixing bowl
• Colander, funnel and beakers - optional, but great for messy fun!

Instructions for making cornflour gloop

• Fill a cup with cornflour and pour it into a bowl
• Add water slowly, mixing with your hands, until you get a sticky, slimy gloop.
• If you want to make it coloured, add some food colouring ( be careful this can stain skin and clothes).
• Play with the slime and see how it behaves. Can you make it into a ball? What happens if you throw it onto the floor?

The Science of Oobleck

Did you notice that if you make a ball with oobleck or gloop, it feels solid, but if you drop the oobleck on the floor, it turns liquid again? The cornflour and water mixture is a Non-Newtonian fluid as it doesn't flow like liquids normally do.

Cornflour gloop ( oobleck )  is made up of molecules arranged in long chains. When the chains are stretched, the liquid will flow, but when you force them together, they stick together to form a solid.

Cornflour Slime Play Ideas

Try squeezing the cornflour gloop into a ball. It should feel solid. Open your hand and watch as the cornflour slime runs through your fingers.

Can you freeze the gloop? Our frozen Kool Aid oobleck smelled wonderful.

Try pouring the slime through a colander. What happens? Can you use the slime to trap a small figure or pretend spider?

Housing a Forest makes oobleck dance!

Try adding more and less water to find out if it changes how the oobleck flows.

Oobleck Challenge

Fill a tray of oobleck and try to walk on it!

I also have a printable instruction sheet available for this. Go to the experiment instructions page to find it.

If you liked this activity, you might like our other messy play ideas, too!

Once you're finished with the oobleck, leave it somewhere warm to dry out. Then, you can either save it to use again or throw it away.

This activity is also part of my playful science series, which is full of play-based science activities for kids.

The post How to make oobleck appeared first on Science Experiments for Kids.

The recent mini heatwave in the UK meant we needed some serious help cooling down, so we had another go at making homemade slushy drinks!

To make a slushy drink, you need to partially freeze a delicious fruity liquid. This can be fruit juice, smoothie, flavoured milk or anything else you enjoy the taste of.

What is freezing?

Freezing is the process in which a liquid turns into a solid when its temperature drops below its freezing point.

What is melting?

Melting is the point at which a solid turns into a liquid.

Is freezing and melting point the same?

Apart from a few exceptions, the freezing and melting point of a liquid are usually the same temperature.

There are several ways to make a homemade slushy drink. You can freeze a ready-made smoothie in an ice cube tray and then experiment with how to make the cubes melt enough to drink or use salt and ice to freeze your slushy. The ice and salt method is the fastest!

Make a 5-minute slushy drink with ice and salt

What you'll need

Two plastic sandwich bags - these must seal securely

Smoothie or fruit juice

Ice

Salt

Kitchen towel

How to make a homemade slushy drink

Pour some smoothie or juice into one of the plastic sandwich bags and tightly seal the bag.

Add a good amount of ice and salt to the second sandwich bag. Place the smoothie bag inside this one and give it a good roll around. If it gets too cold to hold, cover it with a towel, but keep rolling the bags so the smoothie bag is mixed into the ice and salt mixture.

You should find that after a few minutes, your liquid smoothie turns into slush!

Make sure the smoothie bag doesn't split, as the salt will spoil your lovely slush drink!

Why does salt and ice freeze a liquid?

When salt is mixed with ice, it makes the ice melt as it lowers the freezing point of the ice. This is known as freezing point depression. The more salt you add, the lower the freezing point ( up to a point, it won't keep going down forever). For the ice to melt, heat must be absorbed from the surroundings ( in this case, the smoothie mixture ), causing the smoothie to freeze.

Make a slushy drink with ice cubes

If you choose to make a slushy drink with ice cubes, you can also turn it into a simple investigation.

• Set up two or three glasses with the same number of ice cubes and place them in different places to see which melts first, or do the opposite and try to stop the smoothie cubes from melting by covering them with foil and/or bubble wrap.
• Investigate to see which colours you can make with the different juices

Top Tips

Let the juice cubes melt a little bit before removing them from the ice cube tray. They will feel sticky to start with. This is because the ice is so cold it freezes the moisture in your fingers.

Why does ice take up more space than water?

Did you notice that the frozen juice took up more space in the ice cube tray than the liquid juice? This is because as water molecules freeze, they link together, forming a structure with big holes. The gaps in the frozen water mean it takes up more space than when it was a liquid.

We call the temperature at which water changes from a liquid to a solid it’s freezing or melting point. The two are usually the same, but liquids can be cooled below their freezing point. We can cool water or a drink using a mixture of salt and ice, which brings me to the next slushy-making method.

Reading confetti has another fun twist on this method, and made slushy drinks using a salty ice core. I really want to try this.

You can also use this method to make ice cream and cool a drink down very quickly!

Science concepts

• Changes of state
• Cooling
• Melting

Great for:

Science at home

School science club

Just for fun

If you enjoyed our homemade slushy drinks you'll love my book full of edible science experiments!

Affiliate links

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We have had lots of fun blowing up a balloon with lemon juice today, although it's taken several attempts to perfect our technique. This is a brilliant chemistry experiment for learning about chemical reactions!

Inflate a Balloon with Lemon Juice

What you'll need

A small bottle or jar
Lemon juice
Vinegar
Bicarbonate of soda
Balloons

Instructions

Stretch the balloon a bit first. This makes it easier to inflate.

Fill your jar or bottle about one quarter full with lemon juice.

Use a funnel to tip the bicarbonate of soda  ( baking soda ) into the neck of the balloon.

Place the balloon over the top of the bottle. When you're ready tip the balloon up so the baking soda drops into the lemon juice.

Watch the balloon inflate.

Another way to do this is to pour the baking soda directly into the jar and then quickly place the balloon over the top, but we've found this a bit trickier.

Extension Task

Set up a fair experiment to investigate whether vinegar, lime or lemon juice produces the most gas? Think about how you can measure the amount of gas produced.

Think about which conditions you need to keep the same...( amount of baking soda, amount of vinegar, and amount of vinegar and lemon juice )

Why does lemon juice inflate a balloon?

The balloon should inflate because adding the lemon juice/vinegar to the bicarbonate of soda creates a chemical reaction. When the two combine they create carbon dioxide. The gas rises up into the balloon blowing it up.

This is an example of a reaction between an acid ( lemon juice/vinegar ) and a base.

More Baking Soda Experiments

Try some more fun chemistry experiments for kids.

Have a go at one of my 10 brilliant baking soda experiments!

The post Blow Up a Balloon with Lemon Juice appeared first on Science Experiments for Kids.

These magnet powered cars are very easy to make and great for some competitive fun this Easter. My 10 year old and I had a brilliant time trying to build a car big enough to hold an egg safely, but small enough to move easily. It's a bit of a fine balance!

You'll need

K'nex/LEGO or other construction toy for the frame

Plastic eggs

Magnets

How to build a magnet powered car

First, you'll need to build a frame for your egg. The lighter the car as a whole, the easier it will be to move, so we made our frames as small as possible.

Once you've made your car, check it holds the egg securely, place a magnet inside the egg and you're all set.

Use the magnet wand to propel the car forward. This takes a bit of practice, as if you hold the wand the wrong way, it will attract the egg and pull it towards you rather than push it away.

TAKE CARE with magnets. Adults should supervise at all times.

Extension Task - magnet powered cars

Can you build a bigger car and use two eggs to make it move?

What happens if you add extra magnets to your egg?

Not all metals are attracted to magnets, but iron and steel ( steel is mostly iron ) are.

How do magnets work?

Magnets attract some objects but not others. Did you know magnets can also be different strengths?

Magnets have two poles, we call one the north pole and one the south. Depending on which poles you place together they can either attract each other or repel. Opposite poles attract. This activity uses the fact that magnets repel to move the car. The magnet inside the egg tries to move away from the magnet wand, making the car move.

More Easter Science Ideas

Try our other Easter science experiments and investigations, including lots of fun egg experiments.

I've also got some easy Easter STEM Challenges you might like.

Or try one of our fun magnet experiments for kids.

The post Magnet Powered Egg Cars 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.

Making pH test strips is surprisingly easy and I was very impressed with how well they worked. These are a lovely alternative or additional activity to making red cabbage indicator solution and fantastic for learning about the pH scale.

How to make pH indicator paper

You'll need

Red Cabbage Indicator - made by boiling chopped red cabbage in water for 10 minutes

White filter paper

Vinegar/baking soda/lemon juice to test

How to make pH test strips

Dip a piece of filter paper into the red cabbage indicator and leave to dry.

Once dry, drop the solutions to test onto the paper and watch as the colour changes

Solutions can be acidic, alkaline or neutral:

• an acidic solution is when an acid is dissolved in water
• an alkaline solution is when an alkali is dissolved in water
• solutions that are neither acidic nor alkaline are neutral.

Pure water is neutral.

What is a pH indicator?

An indicator is a substance that changes colour when added to an acidic or alkaline solution.

In a laboratory either Litmus or Universal Indicators are used. Litmus can only tell us if a substance is an acid or alkali while Universal Indicator tells us how strong the acid or alkali is.

What is Universal Indicator?

Universal Indicator shows the pH of a substance as it changed colour depending on the strength of the acid or alkali.

The post How to make pH indicator test strips appeared first on Science Experiments for Kids.

Do you know how make a naked egg? It's super simple and a great fun science experiment for kids of all ages. A naked egg is an egg with no shell. Can you imagine such a thing? The shell dissolves in vinegar, but the membrane stays intact.

Naked Eggs

What you need to make a naked egg

Raw eggs

Jar

Vinegar

How to remove the shell from an egg

Place a raw egg in a jar and completely cover with vinegar.

Leave for 24 hours and rinse gently under cold water, carefully rubbing away the shell. If there's still some shell left, put the egg back in the vinegar and check again after a few hours.

The shell should rub off as a white powdery substance. Once you've removed the shell you'll find the egg feels rubbery and is a bit bigger than when it had the shell. This is because some of the vinegar has moved into the egg through the membrane by a process called osmosis.

Top Tip

You can speed the process up by rinsing and changing the vinegar every 3 hours.

Why does the egg shell dissolve in vinegar

The acid ( acetic acid in the vinegar ) reacts with calcium carbonate in the egg shell. This dissolves the eggshell leaving just the membrane behind.

You should see bubbles appear when the egg in in the vinegar, this is carbon dioxide being released as part of the reaction.

Fun things to do with naked eggs

Bounce them! Try dropping your naked egg from different heights, starting  low and then moving higher until the egg breaks.

Use your egg with no shell to learn about osmosis. The egg membrane is semi permeable which allows water to pass through it. If you put place the egg in coloured water you'll find the egg turns the colour of the water!

More Egg Experiments

Try one of these fun Eggy experiments.

 Use eggs to learn how to keep teeth healthy. The composition of egg shell is similar to teeth so makes a great substitute as you obviously can't experiment on your own teeth!

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My 6-year-old came out of school last week incredibly happy and excited as he had spent the afternoon building a candy house. As soon as we got home, he wrote me a shopping list of what we needed to do a similar activity at home. This would also be great for a Three Little Pigs experiment or Charlie and the Chocolate Factory themed science investigation.

We discussed what we wanted to achieve and decided to split our project into two stages, building on the knowledge he'd already gained from school.

If you like this activity, there are 60 more easy edible experiments in my book - Snackable Science

Candy House STEM Challenge

What are the best sweets for 'bricks'?

We decided marshmallows were too soft and not the best shape, but fudge rectangles would be perfect.

What can you use to stick the candy together?

We decided the material used to stick the sweets together needed to be sticky and harden over time, so we thought we'd try very thick icing sugar and marshmallow fluff.

How can you test how strong the house is?

We didn't want to waste too much fudge in our testing ( although it did all get eaten ), so we decided to build two small walls to test our sticky substance.

We discussed what we needed to keep constant and what needed to change.

Variables

• Icing
• Marshmallow fluff

Constants

• The amount of fudge.
• The amount of sticky substance
• Time left to harden

We used the same number of fudge pieces for each wall and tried to use the same thickness of icing or marshmallow fluff roughly, but this wasn't entirely accurate.

Both walls were left overnight to harden.

How to test for stability/strength

1. Pick up the wall and see if it stays intact.

2. Roll a marble to the wall -  try to roll at the same speed and in the same direction for each wall.

Candy House Results

Observations

The icing sugar hardened completely, while the marshmallow fluff stayed soft and sticky.

Marble Test

The icing sugar wall fell over.

The marshmallow fluff wall stayed upright, but possibly because it was so sticky, the marble stuck to it, losing some of its momentum.

The pick-up test

The icing sugar wall remained in one solid piece when picked up.

The marshmallow fluff wall fell to pieces.

How can we improve this test?

Neater application of the marshmallow fluff so the outside of the wall was less sticky.

Place both walls in the fridge overnight to encourage the marshmallow fluff to set.

Next steps

Build a complete house, finding a suitable material for roof tiles.

Suitable for Key Stage 1 Science

Brilliant for starting to learn investigative skills.

Extension tasks

Try to build a stable structure using building blocks or straws and plasticine.

Build a spaghetti and marshmallow structure.

Think about how to construct a strong roof.

Making a gingerbread house and testing that for strength is also a fun variation of this activity.

More edible science experiments

Try one of my other edible science activities, STEM Challenges and experiments.

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I didn't measure the ingredients at all.

To make plastic milk, you will need

• Semi-skimmed milk
• White vinegar
• Food colouring
• A sieve
• Cookie cutter

Plastic milk instructions

• Pour about a cupful of milk into a pan, add some food colouring if you want it coloured, and heat until bubbles start to form. Be careful and ask an adult to help.
• Add a tablespoon of white vinegar and watch the solid and the liquid parts of the milk separate.
• Filter carefully using the sieve.
• Leave to cool and then mould as you wish

Why does milk separate into curds and whey?

Milk contains proteins and fats suspended in water. If the milk is fresh, the proteins move around freely. When the pH drops, the protein molecules stick to each other, creating lumps ( curds ). The liquid left behind is known as whey.

Curdling ( when milk separates ) is a sign that the milk has started to go off. The curds are made from casein. Casein protein chains in milk are usually curled up and dissolved, but the vinegar makes them take a different shape and form lumps that can be moulded into shapes.

This activity can also be found in my book GROSS SCIENCE!!

More science experiments using milk

Learn about emulsions with a colourful magic milk display!

Find out how to make glue from milk.

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After watching this YouTube video of Steve Spangler popping film canisters on the Ellen Show, I knew I wanted to give it a go. I had been intending to pick up some canisters on my next shopping trip, but yesterday, I spotted a little effervescent tablet container in the cupboard. I didn't want to waste the tablets and didn't have any Alka Seltzer, so I decided to try some baking soda and vinegar instead.

How to make a Baking Soda Popper

What you need

• A container with a lid
• Vinegar
• Baking Soda
• Kitchen Roll

Baking Soda Popper Instructions

I added about a cm of vinegar to the bottom of the canister, dropped in a little baking soda, put on the lid and stepped back. The top flew off almost immediately.

To try and slow the reaction down, I wrapped the baking soda in a small piece of kitchen towel, which gave me enough time to put the canister down and grab a camera.

Remember to stand back straight away as these fly with a bang!

Baking Soda Popper Challenge

Can you try turning the canister upside down and popping the canister rather than the lid?

Why does a baking soda popper work?

Baking Soda is alkaline and reacts with acids like vinegar, releasing carbon dioxide ( a gas ) and water. The carbon dioxide gas builds up behind the lid of the canister.  The gas has nowhere to go and is constantly being released by the reaction between vinegar and baking soda.  More and more bits of gas squeeze into the tube, jostling with each other.  The pressure builds and builds until suddenly, the lid of the canister can't take it any more and explodes off the main body.  

The timing is fairly random, so taking a good picture can be frustratingly hard.  Can you take a photo of the lid popping off? I'd love to see it if you can.

* Be very careful with this activity. The top of the canister shoots up at speed. Make sure all little and big people are well out of the way.

If you like this activity, you'll love my full collection of baking soda and vinegar science experiments!

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Do you know why pop rocks pop? We're going to find out in this easy kitchen science investigation.

Why Popping Candy ( Pop Rocks) Pops

We all tried the popping candy first and giggled as it burst tickling our tongues.

Pop Rocks Experiment

We decided to see what else would make the candy burst, so placed some in oil, water and vinegar.

What you need:

• Popping candy / Pop rocks
• 3 bowls
• Oil
• Water
• Vinegar
• Anything else you want to try

Instructions

• Open the pop rocks and place a small amount in each bowl.
• Add water to one, oil to another and vinegar to the third.
• Observe what happens.

We found the candy in the oil didn't do anything.

The candy in the water fizzed and bubbled.

The candy in the vinegar fizzed and bubbled faster than that in the water.

Why does popping candy pop?

Pop rocks are made by heating the ingredients and then exposing to Carbon Dioxide ( a gas ) at very high pressures before allowing to cool. Tiny bubbles of gas are trapped in the popping candy.

When you put the candy in your mouth, saliva breaks it down and releases the carbon dioxide, which makes a popping sound.

The water acted like saliva to break down the candy and release the bubbles.

The oil didn't break down the candy, therefore it remained intact.

Vinegar is acidic, and so reacted faster than the water with the candy.

More Pop Rocks Experiments

Can you think of another experiment? How about a fizzy drink?

Can you design something to keep the pop rocks safe under water?

For more kitchen science ideas try on of our 50 kitchen science experiments!

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An unbreakable egg sounds impossible. We think of eggs as fragile ( how many times have you opened a box of eggs to find one broken ), so how do you make an unbreakable egg?

How to make an egg unbreakable

How to make an unbreakable egg

You'll need

• an egg
• cling film

Instructions

Wrap the egg in cling film, place it in your palm and close your hand around it so your fingers are completely wrapped around the egg.

Squeeze as hard as you can.

The egg should remain in one piece.  If you are feeling extra brave, you could try it without the cling film.

Why can't you break the egg?

If you've ever dropped an egg, you know the shell is fragile, but the shape of an egg is very strong. If pressure is applied evenly over the shell, it will not break.

We tried REALLY hard to break the egg, but it stayed in one piece!

Did you know - egg experiments

A fresh egg will sink in water; a stale egg will float. Now, there's something I want to try!

Try spinning a boiled egg and a fresh, unboiled egg. You should be able to tell the difference between them based on how they spin.

Discover why dome shapes are so strong.

Another way to make an egg float is to add some salt to a bowl of water.

Or, try one of my other eggy experiments.

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I love treacle toffee, it always reminds me of bonfire nights where we'd go out wrapped up warm in hats and scarves with everything smelling a bit smoky. This treacle toffee recipe is a great way to explore changes of state, as you have to melt the sugar first and then leave it to harden.

What you need to make treacle toffee

500g brown sugar

150ml water

¼ tsp cream of tartar

75g butter

100g black treacle

100g golden syrup

Treacle toffee recipe

• Place the sugar and water in a pan and heat, stirring gently. The sugar will melt, and the two liquids combine.

• Add the rest of the ingredients and heat gently for about 10 minutes. You need to get the mixture to 143oC, which is known as the soft crack stage. If you don't have a sugar thermometer, carefully drop a little of the mixture into cold water. When it separates into threads which are hard but not brittle, it is ready.
• Pour into an oiled tin, and leave to set. You can either mark the mixture with a knife before it sets or break it with a little hammer later on.

As we made the toffee, I showed the children the sugar in its solid state and asked them how they thought we could melt it. My 4-year-old wanted to leave it out in the sun, but we decided heating on the hob might be faster.

As the sugar melted, we could smell a toffee like smell, and as it got hotter and hotter, we saw more and more bubbles.

The science part

This experiment is a great way to demonstrate the process of changing state from solid to liquid and back again.

Everything we know exists in three states: A solid, A liquid or a Gas!

Substances can change from one state to another by different processes.

SOLID  ––> LIQUID = MELTING

LIQUID ––> GAS = EVAPORATING/BOILING

GAS  ––> LIQUID = CONDENSING

LIQUID ––> SOLID = COOLING/FREEZING

When the sugar was heated, it changed from solid to liquid which is an example of melting, and when we move back from a liquid into a solid, it is an example of cooling/freezing.

The reason this happens is that when you provide heat, the particles that make up the solid are given energy which causes them to vibrate, which breaks the bonds holding them together. As they cool, they lose this energy and so form bonds again, but not in the same shape.

At the soft crack stage, the amount of water left in the mixture is very low. This gives a hard but still chewy toffee. For harder toffees and lollipops, you need to heat to the hard crack stage when there is almost no water left.

A much simpler way to demonstrate changes of state would be to melt chocolate and make rice krispie cakes!

More kitchen science for kids

Discover the science of meringue, have a science bake off or try one of my other delicious kitchen science experiments for kids.

The sugar mixture gets very hot, always ask an adult to help

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Today we set about exploring some lovely pumpkins from a local farm. Before we carved them up, we weighed and measured them.

I gave the children 2 medium sized pumpkins and asked them to feel them and think about which was the heaviest. After they guessed, we weighed the pumpkins to see if they were correct, and they were.

We then measured the pumpkins around the middle and Z measured his own waist, wrist and head. The heaviest pumpkin had the largest circumference.

I opened up the pumpkin, and we all looked inside. Z said it was cold, orange and squishy to the touch.

Together we removed all the seeds and counted them by putting into groups of 10. This took quite a long time!

Daddy then helped to carve a spider. What do you think?

More things to do with pumpkins

These non spooky pumpkins from Smart School House are brilliant!

This pumpkin invitation to play from I Heart Crafty Things is beautiful.

You'll love our easy pumpkin themed lava lamps.

Finally, I have lots of ideas for things to do with leftover pumpkins!

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Lava lamps are one of my favourite things to make. They are very easy to make but really impressive for children to watch.

I also have a pumpkin lava lamp you might like.

You will need

• A clear plastic bottle or jar
• A bottle of vegetable oil
• Water
• Alka Seltzer
• Food colouring (a spooky colour )

Instructions

Fill the bottle or jar a quarter full with water.

Top up to the (near) top with the vegetable oil.

The oil and water should separate into two layers, water at the bottom and oil sitting on top. Add about 6-8 drops of food colouring once they have separated.

Pop in half an Alka Seltzer tablet and watch the bubbles form.

Add more Alka Seltzer bit by bit to keep the bubbles rising and falling.

Whatever you do, do NOT shake them up as my 2-year-old did. Let's just say it was very messy!

What's going on?

Firstly, water and oil do not mix - this is because water is a polar molecule - its structure means that it has a positive charge on one end and a negative charge on the other. Water molecules stick together because the positive end of one water molecule is attracted to the negative end of another.

Oil molecule structure is different - it is non-polar, meaning that its charge is more evenly spread out, so the oil is not attracted to water - in fact, we call it hydrophobic (water-fearing) as it tries to get as far away from water as possible and will not mix.

The reason that oil rests on top of the water rather than underneath is because it has a different density to water.

As the alka seltzer is added (this is made of citric acid and sodium bicarbonate), it reacts with the water to form carbon dioxide gas and sodium citrate. It is the carbon dioxide bubbles that carry the coloured water to the top.

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We love a good baking soda experiment. I spotted this brilliant and simple idea on Reading Confetti, who kindly said I could post it here. These are our fizzing rocks.

How to make fizzy rocks

You'll need

Water

Bicarbonate of soda/baking soda

Vinegar

Food colouring

Instructions

Mix a little water with the bicarbonate of soda. I used a whole packet of bicarbonate of soda and added water slowly until I had a very thick paste type mixture.

Add a few drops of food colouring, mould the paste into rock shapes, and leave it to dry for a few hours.

Once the rocks have hardened, slowly add vinegar and watch as they fizz and dissolve.

The science behind baking soda rocks

Vinegar (an acid ) and bicarbonate of soda ( an alkali ) react to neutralise each other. This reaction releases carbon dioxide, a gas that causes the bubbles you see.

Other ideas

Add small objects to the rocks and drop them into a bowl of vinegar like Reading Confetti did.

Make one big rock and see how much vinegar is needed to dissolve it.

Try one of my other fantastic baking soda experiments.

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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.

The post How to make a lemon sink? appeared first on Science Experiments for Kids.

We've talked about respiration before when we made bread and used yeast to make the dough rise. Blowing up a balloon with yeast is another very easy experiment to demonstrate respiration in action and is quicker than making bread if you are short of time.

What is respiration?

Respiration is a chemical reaction which occurs in animal and plant cells. It releases energy from glucose. Aerobic respiration needs oxygen, but anaerobic respiration doesn't need oxygen.

Anaerobic respiration produces less energy than aerobic respiration. It occurs in humans when not enough oxygen reaches muscle cells ( for example, during hard exercise ). Bacteria and other microorganisms can also use anaerobic respiration, and yeast actually carry out an anaerobic process called fermentation.

Respiration occurs in the mitochondria of cells. You can find out more about mitochondria by making a model of a cell.

Blow up a balloon with yeast

A balloon

A small clear drinks bottle

A packet of dried yeast

Warm water

1 teaspoon of sugar

Instructions

1. Blow the balloon up a few times to give it some stretch. This just makes it easier for the experiment to work.

2. Fill the small bottle about 3cm full of warm water.

3. Add the yeast and 1 teaspoon of sugar.

4. Place the balloon over the open top so no air can escape.

5 Over the next half an hour, watch what happens. (Obviously, do other stuff and come back, it may be a little boring to actually watch it for half an hour!)

Yeast and Respiration

Yeast is a living organism. In order for it to survive, it needs to make energy. In its dried form, the yeast is dormant, but as soon as you provide it with warmth, water and sugar (its food), it 'wakens' and becomes active. The yeast uses the sugar (glucose) and oxygen from the bottle to make water, energy and carbon dioxide. Carbon dioxide is a gas, and this is what you see filling the balloon.

Remember, yeast can respire anaerobically when there's not enough oxygen for aerobic respiration.

Fermentation

Glucose -> ethanol and carbon dioxide + energy

Aerobic Respiration Equation

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

The image is taken from Snackable Science which contains SEVENTY fun edible experiments and investigations!

Science concepts

Enzymes

Respiration

Contains affiliate links

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Jelly is a great way to learn about changes of state as first it dissolves in hot water and then sets to become solid as it cools.

Why does jelly set?

Jelly sets because of a protein called collagen. Collagen is made up of three protein fibers wrapped around each other.

Jelly contains gelatin, which is made from collagen from animal bones and skin. When the gelatin is heated and mixed with water, the protein fibers unravel and come apart, so the jelly from the packet melts. As the jelly cools, the fibers coil up again, trapping water between them, which makes the jelly set.

We watched the jelly from the packet melt as we added the hot water and talked about bonds breaking down and how they reform as the jelly cools, causing it to set.

We also tried mixing different colours of jelly, which was a fun way to learn about primary and secondary colours.

To make multicoloured, layered jelly, you need to let each layer set before adding the next.

Do you know fresh pineapple stops jelly setting?

What other colours do you think we could make?

Suitable for KS1 - changes of state.

Don't forget to check out my other kitchen science experiments.

The post Why does Jelly Set? appeared first on Science Experiments for Kids.

Looking at food groups is such a fun thing to do. It gives children a real insight into the types of food they eat, and you can use it as an opportunity for taste testing.

For younger children, you can introduce food groups in terms of what they are: There are five basic groups.

Then on an old plate or paper plate, divide it into five with a whiteboard pen board pen and label as the groups - this will easily wash off, and using the sheets below cut out the foods and add them to the plate portion you think they belong too.

Food groups work sheet

You can then ask your child which ones they would like to try and maybe plan a trip to the shop to purchase and hold a little tasting session.

Moving forward with older children, you can then introduce the nutrient food groups.

There are seven basic nutrient food groups. These include:

Each group is needed by the body for different reasons and can be found in different types of foods.

I have included this table for you to use in a sheet below.

Food groups Table

Food Group Activity

Take an empty muffin tin, and in each of segment put a different type of food.

Make some flags using cocktail sticks and paper and label each one with a letter to represent the food group.

Discuss each food describing how it looks and maybe taste it to see if that gives any clues - is it rich or grainy or smooth like dairy? Then stick a flag into the food that it belongs to!

Finally, you could then print out the table above, chop it up and use it as a card for a revision exercise.

Have Fun

Kerry

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Bubbles are one of the most fun things to play with...but what colour are they?

Transparent? Clear? See-through?

Did you know you can see all the colours of the rainbow in bubbles?

How to make rainbow bubbles

An empty clear bottle

Washing up liquid

Water

A sink

An overcast day (works best)I

Fill the bottle about three-quarters full with water

Add a squirt (scientific measuring there) of washing up liquid

Quickly tip the bottle and pour the water out fast.

You will find that the bottle is left full of bubbles.

These will look clear and normal, to begin with, but place the bottle on a windowsill and wait and watch over the next 30 seconds.

You will find that the bubbles will start to show signs of colour that will get stronger and stronger and that each bubble will look like it has been coloured like a rainbow!

Why can you see a rainbow in bubbles?

Visible Light from the sun is known as white light. It contains a range of colours, all with different wavelengths that, when together, form white light.

The colours of the rainbow are:

Richard Of York Gave Battle In Vain

Red, Orange, Yellow, Green, Blue, Indigo and violet

When white light from the sun shines through the film of the bubbles, the light is reflected and dispersed, splitting white light into its different wavelengths, revealing all the colours of the rainbow!

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'Thank crunchie, it's Friday' seems the perfect phrase for today's experiment as it involves learning how to make honeycomb with our easy honeycomb recipe. Once you've made the honeycomb and learned about the science behind the bubbles, the rest is up to you. Add melted chocolate, sprinkles, popping candy or anything else to make it an even tastier treat.

Easy Honeycomb Recipe

Honeycomb ingredients

100g of sugar

1 tablespoon of water

2 tablespoons of golden syrup

1 teaspoon of bicarbonate of soda

How to make honeycomb

1. Put all the ingredients except the bicarbonate of soda into a saucepan and place on a low heat

2. Line a baking tray with silver foil.

3. Stir the mixture until all the sugar has dissolved. Raise the heat slightly so that it bubbles, and stir occasionally until you cannot feel any sugar at the bottom of the pan.

4. Take the pan off the heat.

5. Add the bicarbonate of soda and stir!

5. Watch what happens - it should froth up with lots of lovely bubbles.

6. Pour the mixture into your baking tray or into a mould.

7. Allow the honeycomb to cool. When it's solid, carefully break it up into tasty treats. Add any extra ingredients or crush and sprinkle over ice cream!

Why is honeycomb full of bubbles?

The bicarbonate of soda breaks down with heat to release carbon dioxide gas. The gas causes the sugar and syrup mixture to froth and bubble. The bubbles become trapped in the mixture, where they set as the mixture cools.

This activity is one of many delicious kitchen science experiments you can find in Snackable Science!

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Curdling is a process by which a liquid is transformed into a soft semi-solid or solid mass. We can see this happen in a straightforward experiment!

Milk is made up of proteins, fats, sugar and water. The protein molecules ( mostly casein ) are suspended in the liquid, where they move freely. Milk is a mixture called an emulsion. When an acid is added, the pH drops, causing the proteins in the milk to stick together ( coagulate ), forming lumps ( curds ).

You'll need

Orange or lemon juice

A glass

A spoon

Milk

Sieve

Method

1. Half-fill the glass with milk

What does the milk look like?

What is its texture?

Can you see bits in it?

2. Fill the rest of the glass with your orange juice

3. Stir the milk and orange juice. What happens?

Milk can also be curdled by heating it in a pan and adding vinegar.

Why does milk curdle?

Usually, when we curdle something, we have done something wrong in the cooking process. Curdling is usually caused by acids and milk or eggs being added incorrectly or when a liquid is heated for a long time. Curdling does have some benefits, though, and it is the method used to make cheese. Soft cheeses like ricotta and brie are examples of 'curdled cheese'.

The post Why does milk curdle? appeared first on Science Experiments for Kids.

It is so annoying when getting to the end of a ketchup bottle, and you have to keep banging to get that last bit out. Why is this? Because ketchup is thick and does not flow as easily as other fluids. We call this resistance to flowing viscosity.

The rate at which different fluids flow can vary considerably.

So how about having races to test them?

What you will need:

Stopwatch/tape measure

A ramp - we used a table that we took two legs off.

Different fluids to test  

We used whole milk, ketchup, chocolate sauce, orange juice and cooking oil

Deciding what to measure

• you could decide to time how long it takes for all five fluid to reach the bottom of the table
• you could decide to measure how far they have travelled after a certain time

How to make the test fair

You need to consider the things that could impact on it not being a fair test - this could include things like

• ensuring the volume use use is the same for all fluids
• ensuring that you time the flow for the same distance
• ensuring that measure after a set time for each.
• ensuring you repeat the investigation 3 times and take a mean result
• The gradient of the ramp is the same for each fluid

Method

You can either do one at a time - this is easier for recording time, or tip them all at the same time if you want them to get to the bottom of the table.

Let them flow for the set time you have decided, or time them until they all reach the bottom.

You can record your results in a table.

Results 

We decided to wait until they got to the bottom but had to stop the experiment as it was clear the ketchup was never going to make it! Next time we will try with measuring the distance travelled!

Have fun

Kerry 

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We love a science experiment that seems like a magic trick, and this activity is one of the best. We're going to find out how to make hot ice.

Imagine saying to people, 'I can make hot ice!' They wouldn't believe you would they?

As far as science theory goes, they shouldn't, we know that in order for ice to exist, it has to be at 0^oC and that when heated it melts.

Note - this activity does not make ice, just something that resembles ice. It is NOT edible, so please discard the solution when you have finished experimenting.

How to make hot ice

To make hot ice, you will need

1 litre of acetic acid (white vinegar)

4 tablespoons of bicarbonate of soda ( baking soda )

Pan

Hob to heat the mixture

Jug

Fridge

Spoon

How to make hot ice

Pour the white vinegar into the pan.

Carefully add the bicarbonate of soda, half a tablespoon at a time and stir the mixture until it has all dissolved.

The baking soda and vinegar will fizz as they react together, which is why you need to add the baking soda slowly. You have now made a solution called sodium acetate. Carbon dioxide gas is also given off.

Simmer the solution on the hob until it has reduced to about 100ml. This should take about one hour. The solution is now supersaturated!

Once the mixture has reduced down, pour it into a jug, cover it and place it in a fridge to cool for 1 hour.

Once cooled, you can pretend the liquid is water to your friends and pour it out onto a surface. It should begin to crystallise straight away, forming towers of 'ice'. It looks and feels hot because the reaction gives off heat. It is exothermic.

The great thing is you can remelt the 'icicles'  to reuse when you want to perform the trick again! We put the jug in the microwave for 40 seconds to dissolve the crystals and then placed it back in the fridge for an hour.

If pouring isn't working, try warming up your finger and gently touching the surface of the liquid. It should start to crystallise from your finger and spread outwards.

How does hot ice work?

Sodium acetate exists as a supercool liquid in the fridge, meaning that it is in liquid form below its usual freezing point. As soon as it is disturbed, it starts to crystallise. The crystallisation is an exothermic reaction which is why we call it hot ice!

Sodium acetate usually freezes at 54^oC, but as you have seen can exist in the supercool form below that temperature.

Uses of sodium acetate

• Sodium acetate is used in heat packs and hand warmers. Heating pads usually have a metal disc in them, which, when clicked, starts the crystallisation process, releasing heat. Hand warmers can usually be reused by boiling the pouch to melt the contents.
• As a flavouring in food.

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When I brought out the spaghetti and marshmallows, I think my children thought we were having some kind of weird and wonderful dinner, not building structures.

This is a great STEM activity for children of most ages, as you can tailor it to their understanding. I let my 2-year-old build whatever she wanted, and she had a great time working out how to put the spaghetti in the right places. With my 4-year-old, we were a bit more structured and tried to build a tower.

Older children can think carefully about which shapes are strong shapes and will support their structure the best.

How to build a marshmallow tower

You'll need

Spaghetti ( uncooked! )

Marshmallows

Instructions

Snap the spaghetti into smaller pieces.

Push the ends of the spaghetti into the marshmallows to build different shapes for your tower.

We started with a cube, but when we put weight (Pooh bear in our case) on it, it started to lean very precariously to the right, and one of the vertical spaghetti pieces snapped. We then discussed what we would do to make it stronger. We decided to add some diagonal pieces, which seemed to do the trick.

We thought it would be fun to try lots of different shapes to see if we could break them. Straight lines and marshmallow corners tend to lead to triangles, but we had a lot of fun with other shapes, too.

Extension task

Make it a game. Challenge friends or family to see who can build the tallest tower!

Try miniature and then giant marshmallows. Which are easiest to build with?

Stable structure secrets

Triangles are great for making a stable structure.

Consider where the centre of gravity is in your tower. A wide base helps stability, giving a centre of gravity low down and central.

More engineering challenges

Discover why domes are so strong with this eggshell bridge!

Build a famous monument with newspaper!

Build bridges with different shaped paper and cardboard to investigate which is the strongest!

Frugal Fun for Boys and Girls has a fantastic LEGO bridge building challenge you might like too!

The post Marshmallow Spaghetti Towers - Engineering Challenge appeared first on Science Experiments for Kids.

Today we are looking at the difference between things being wet and dry. This investigation is so simple I did it with my 18 month old,  who loved dipping her fingers in the different pots and saying 'wet', so it is a great preschool science activity but can also be extended for older children.

What you need

• Some small pots 
• A waterproof bag ( not transparent )
• Different materials - for example rice, pasta, stone , sponges, cereal, flannels, dried fruit
• Water

Instructions

Let the children touch the wet and dry materials and ask how they feel different. You could also ask them to shut their eyes and try to match the wet and dry versions of the same item.

Extension Activity

Observe how some foods change when placed in water. We looked at shreddies, raisins and bread, and talked about how they grew bigger as they absorbed water.

Don't forget to follow our Pinterest Science board for lots more ideas.

Follow Emma Vanstone's board Science for kids on Pinterest.

The post Preschool Science Experiment - Wet and Dry 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.

Make a yummy Baked Alaska and learn at the same time.

Mmmmm, Ice-cream is one of my and my children's favourite foods. On its own straight out of the tub, or on top of a cone or with a pudding, it is just yummy, but we all know what happens if you leave ice cream out for too long, don't we? Yes, it melts!

Personally, I quite like runny ice cream, but is it possible to keep ice cream cold and not melt and apply heat?

Sounds impossible, doesn't it? but actually, in the simple pudding Baked Alaska, we are going to see this happen!

What you will need:

Some cookies or sponge cake (quite large ones!)

Some ice-cream

3 large eggs

200g of sugar

Mixing bowl

Whisk

Baking tray

Aluminium Foil

Oven

How to make Baked Alaska

1. Firstly, you need to separate the egg yolk from the egg white. The easiest way to do this is to crack the egg into your hand over a bowl. Catch the yolk and let the white drain through your fingers. Put the yolk into a separate bowl. Try to get as much of the white as possible.

2. Add the sugar and whisk together until you have a glossy thick meringue mixture - test it over your head to check that it is stiff enough. If you think it will pour, it is not ready!

3. Pre-heat your oven to the highest gas mark.

4. Line your baking tray with the silver foil. Place on your cookies.

5. Take a scoop of ice cream that will fit the centre of the cookie. Put it into the meringue mix and submerge it until it is totally covered.

6. Put your ice cream scoop on the cookie.

7. Bake the ice cream for about five minutes or until it goes golden brown.

8. Remove it and cool it for a few minutes, so you don't burn your lips and you have a nice yummy pudding!

Why doesn't Baked Alaska melt?

When you whisk up the meringue, you fill the mixture with lots of air bubbles, remember, we looked at transforming egg whites a little while ago!  This acts as an insulating layer around the ice cream and protects it from heat. The heat is unable to penetrate through and so the ice cream stays cold.

So there you have it - science and a pudding all in one! You can't get better than that!

The post The science behind Baked Alaska! appeared first on Science Experiments for Kids.

Do you know you can make homemade glue from milk? All you need is milk, white vinegar and baking soda. The vinegar is used to split milk into curds and whey.

This fun kitchen science experiment is very simple but requires adult help to heat the milk.

How to make glue from milk

What you need:

Milk

White vinegar

Baking soda ( bicarbonate of soda )

Pan

Water

Strainer

Make glue from milk

First, you need to split the milk into curds and whey.

• Heat 1 and a half cups of milk in a pan; once warm, add 3 teaspoons of white vinegar.
• Keep heating and stirring the mixture, and you should see the curds ( solid part ) and whey ( liquid part ) separate.

• Strain the mixture using a sieve. You should be left with solid lumps which can be moulded to make a ball. These are the curds.
• Place the solid mixture back in the pan and add a little water and a tablespoon of baking soda.
• Heat the mixture until it starts to bubble.
• Give the mixture a good stir and leave it to cool. You can now use it as glue. You might need to add a little more water or baking soda until you get the right consistency. It should look like a thick paste.
• I tested ours by sticking two egg boxes together ( both contain eggs, so they are heavy ). It worked!!!

How can you make homemade glue from milk? Why does it work?

Here’s what happened to the milk. The vinegar creates a chemical reaction which makes the milk separate into two parts, a solid (the curds), and a liquid (the whey). The curds are milk protein, called casein. Liquid casein is a natural glue.

When you add the baking soda, it neutralises the vinegar ( which is acidic ). The bubbles are caused by carbon dioxide gas being given off as part of the reaction. The curds form a liquid again after being neutralised.

More science experiments using milk

Learn about emulsions with a colourful milk display made with milk and dish soap.

Curds can also be used to make small decorations. In the early 1900s milk was sometimes used to make buttons and other items! You can find out more about this in my book Gross Science!

The post Make glue from milk appeared first on Science Experiments for Kids.

This experiment looks at how egg white ( albumen ) is transformed as it is whisked. Egg white is about ⅔ of the total weight of an egg and is 10% protein, the rest being mostly water. To demonstrate the change in the egg white, we will find out how to make meringue!

How to make Meringue

Meringue Recipe

What you need:

• A bowl
• A whisk
• Baking sheet
• Four egg whites
• 225g caster sugar

You can use fewer eggs as long as you use about 55g of caster sugar per egg white.

Instructions for making meringue

• Preheat the oven to 140 degrees.
• Line 2 baking sheets with parchment
• Put the egg whites in a bowl and whisk slowly at first then faster as they expand. Once you get stiff peaks, the egg whites are ready.

• Add the sugar slowly a few tablespoons at a time and whisk after each sugar addition.
• Place 2 heaped tablespoons of mixture onto the baking parchment, leave a gap and then repeat until all your mixture is used up.

• Place in the oven on a low shelf for about 45 minutes. Then turn the oven off, but leave the meringues inside for a further 15 minutes.
• Serve with whipped cream and fruit.

For more fun try making meringue towers, how high can you build them before they topple?

The Science Behind Meringue

When we whisk egg white, two things happen:

• The whisk creates a force through the egg white which unfolds the protein molecules.
• The whisking also causes air bubbles to be trapped in the unfolded proteins which makes a foam.

When baked, the foam hardens into meringue! How cool is that?

More Easy Kitchen Science for Kids

If you enjoyed this activity, you'll love my huge collection of kitchen science experiments including a Science Sparks Bake OFF!!

You might also like my new book Snackable Science which contains 60 easy edible experiments for kids!!

The post How To Make Meringue - Kitchen Science appeared first on Science Experiments for Kids.

Welcome to a very eggy week on Science Sparks! Shrinking eggs is the first of 3 egg based experiments, so if you like this one, pop back later in the week to see what else we have been up to! This experiment looks at osmosis.

Osmosis is the net movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration.

Water molecules flow from one side of a membrane to the other until the concentration of water molecules on both sides is equal.

What you need:

• Two eggs
• Water
• Two glasses
• Vinegar
• Sugar
• A pin

This experiment has 3 stages:

Remove the shell from the egg with vinegar

Shrink the egg by placing it into a concentrated sugar solution

Grow the egg by placing it in water.

Remove the shell from an egg

We need to remove the shell to expose the semi-permeable membrane of the egg. This can be done by placing the eggs in a cup of vinegar, so they are totally covered for about 24 hours. After this time wash the egg rubbing away the remaining bits of the shell.

Shrink and grow the egg

Make up a concentrated sugar solution by dissolving sugar in water. Place one egg in a glass of water, and the other in the sugar solution. Our sugar solution looks quite dark as I used brown sugar. Note how the egg in the water sinks to the bottom of the glass while the one in the sugar solution floats. This is because the sugar solution is denser than the water.

• Leave for another 24 hours. You can see the egg in the sugar solution looks much smaller than the one in the water.

Prick the egg from the water with a fine needle and watch a jet of water shoot out!

• Put the shrunken egg in water and watch it grow as it reabsorbs the water, this might take a few hours.

Why does the egg shrink and grow?

The sugar solution is much more concentrated than the water, this is because it contains dissolved molecules of sugar. The dissolved sugar molecules cannot pass through the semi-permeable membrane of the egg, but the small water molecules can. The water moves from the less concentrated egg solution to the more concentrated sugar solution until the concentration of water is the same on both sides. Therefore water moves from the egg to the sugar solution, and the egg shrinks.

When the shrunken egg is placed back in water, the concentration of water inside the egg is lower than the water, so water moves from the water to the egg, making the egg increase in size.

When we pricked the egg that had been in the water, water shot out of the egg. This is because the egg has absorbed water, and so the inside of the egg is under more pressure than usual.

The egg shell dissolves in the vinegar as the acetic acid in the vinegar reacts with the calcium carbonate of the shell. Carbon dioxide is given off during this reaction so you should see bubbles of gas escaping.

Extension Tasks

Weigh the eggs after removing the shell, after they shrink and again after they reabsorb water to see how much water is lost and gained at each stage.

Try adding food colouring to the water and watch as the eggs absorb the coloured water.

Soak a boiled egg in vinegar, this should make the egg so rubbery it will bounce ( from a low height ). You can also bounce a non-boiled egg that has been soaked in vinegar.

Don't forget to wash your hands after handling raw eggs!

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