We all know kids are naturally curious (starting with that head-scratcher, “Why is the sky blue?”). Encouraging that questioning mind with simple science experiments for kids is a great way to foster an early love of science and experiments are a great way to practise STEM learning principles of critical thinking, problem solving, creativity and curiosity. Perhaps, it will even start them on a lifelong love affair with science and with half of the top 20 jobs in demand in Australia requiring some kind of science background or scientific thinking, that knowledge is power. The good news is you don’t need to have a professional lab set up with all the beakers and bunsen burners to do fun experiments at home. Try these cool science experiments for kids of all ages that use common household items or science kits and enjoy expanding their minds. 

Bubble Fun

A huge bubble being blown using two cut straws and a large hoop of string is a simple science experiment for kids.

Suitable for: Ages 5+

This bubble kit comes with all you need to perform amazing fun experiments (including freezing one), but the project that’s best suited for early learners is to see how different experimental conditions can change the size of how big a bubble you can blow. 

What You'll Need

Instructions

Pour the bubble solution into the plastic tray provided and fit the loop that’s included with the kit to the two long bubble wands. Holding a wand in each hand, slowly submerge the loop into the bubble solution. Carefully pull the wands up, holding them together. Separate the wands to open up the loop, then walk backwards while holding the wands out to create your giant bubble. To continue the fun, you can make your own bubble solution – the recipe is in the Bubble Science Kit. 

Get Kids to Ask

  • Try different things to see how big a bubble you can get. What helps make the bubble bigger? (try blowing the bubble slowly rather than quickly, and when there’s no wind)
  • What could you use to measure how big the bubble is? (use your hand to mark where the top of a bubble is off the ground before it pops, then use a tape measure to check its height) 
  • Why do they have a rainbow hue? (White light is made up of all the colours of light. When light shines on a bubble, it bounces off the bubble’s layers of soap and water, and some of it reaches our eyes, which is why we see lots of colours) 

Magic Milk

gif of a paper plate full of milk and food colouring makes colourful patterns once a cotton tip is dipped into it.

Suitable for: Ages 3+

Now this is a children’s science experiment that’s not only fun, but oh-so pretty to watch. All it takes is some milk, food colouring and a cotton bud dipped into washing up liquid and hey presto – colours that dance, swirl and make stunning patterns. Even better? Clean-up is a breeze.

What You'll Need

Instructions

Pour milk (full-fat is best) in a flat dish. Add drops of different food colours to the surface. To make the ‘magic’ happen, dip a cotton bud in dishwashing liquid, shake off excess, then touch the cotton bud to the milk. 

Get Kids to Ask

  • Why do the colours run around? (The negative end of the dishwashing liquid molecules line up with the positive end of the water molecules, causing them to bounce around and zoom over the surface of the milk, moving the food colouring in the process)
  • What happens if you use skim milk? Or cream? (different fat molecules of the milk will have different outcomes)
  • What happens if you use different detergents, such as hand soap or shampoo? (they may have different amounts of molecules)

Paper Plate Sundial

close-up of a white paper plate marked up like a clock on top of grass, with a shadow created by a pencil gnomon.

Suitable for: Ages 8+

Long before wristwatches and alarm clocks came into existence, sundials were used for telling the time. With this simple experiment for kids, little learners can find out how to make a sundial with a paper plate and discover how time was told in ye olde days, thanks to the movement of the Earth around the sun. 

What You'll Need

Instructions

When it’s midday, take a paper plate outside to a sunny spot and poke a pencil through its centre. Then mark the number ‘12’ where the shadow falls. Throughout the afternoon, mark the numbers for 1pm, 2pm, 3pm, etc. If you want to continue the next day before breakfast and countdown to midday, the 12 will be in the same place. You should now have a fully operational sundial ready to tell the time by.

‍Did you know? In the Southern Hemisphere a sundial goes anticlockwise!

Get Kids to Ask

  • Why does the position of the arrow change? (as the Earth rotates, the position of the sun moves relative to Earth, causing the shadows to change position)
  • How could you tell if it was the half hour, e.g. 1.30pm? (shadow falls halfway between numbers)
  • How could you measure time if there is no sun? (hourglass, measuring how far a candle burns in one hour, etc)

Erupting Volcano

gif of a model volcano erupting with red ‘lava’ following a classic baking soda and vinegar kids science experiment 

Suitable for: Ages 8+ 

It’s a classic science experiment for kids for a reason… little people love it! With just a couple of basic household supplies and a ready-to-go kit, you can create a chemical reaction that mimics one of the world’s most impressive forces of nature: a volcanic eruption. 

Did You Know? A volcano is classed as active if it has erupted within the last 10,000 years.

What You'll Need

Instructions

Follow the kit’s instructions to make and paint the volcano using the included products. Once the paint is dry, you can make the volcano explode. Add bicarb soda into the ‘crater’, then mix a drop of red food colouring with vinegar and pour on top. Then stand back and watch it erupt.

Get Kids to Ask

  • What do you think causes the eruption? (the chemical reaction produces a gas that creates a build-up of pressure, pushing the liquid out of the volcano)
  • Would it work with water instead of vinegar? Why do you think that is? (you need the acidity of the vinegar to cause the chemical reaction)
  • What would happen if you added a couple of drops of dishwashing liquid to the vinegar? (it will create lots of little bubbles and a foamy eruption… give it a go and see!) 

Diet Coke and Mentos Eruption

The Mentos and Coke science experiment is easy to do and popular with kids. 

This kids’ science experiment is a firm favourite because of the explosive scientific results and, well, the mess. While kids will love watching a frothing eruption, they will also be witnessing a chemical reaction and nucleation (the first step in the formation of a new structure).

Note: To be safe, this is an activity that requires parental supervision to make sure little scientists don’t get too close to the eruption. Also, as it can get messy, it’s best to do this outside. 

What You'll Need

Instructions

Go outside, put the Diet Coke on the ground and unscrew the lid. Quickly slip the funnel into the neck, then drop down about half a packet of Mentos. The opening of the bottle and the dropping of the Mentos should be done as close together as possible to avoid too much carbon dioxide being released from the bottle. Remove the funnel quickly and stand back from the bottle: watch it blow.

Get Kids to Ask

  • What makes the bubbles in a soft drink? (carbon dioxide)
  • What happens when you open the bottle of Diet Coke? (the carbon dioxide tries to escape)
  • What is the surface of a Mentos like? (it has lots of tiny dimples, which increase the surface area and increase bubble formation)
  • What happens when you drop the Mentos inside the liquid? (it speeds up the process by breaking the surface tension of the liquid)

SEE ALSO: Simple STEM Activities For Preschoolers and Primary Kids

Kids’ Science Experiment Kits

Make STEM activities fun with these easy science experiment kits for kids

Sometimes, as a parent, the best gift is someone else doing all the prep work for you. These other fun science experiment kits are a great start.

What to Try

SEE ALSO: STEM Activities for Kids These Holidays

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This article was originally published in 2020 and has been updated.