15 School Holiday Science Experiments

You know the feeling. It's day two of the school holidays, you've done the park, you've done the movie, and someone has already said "I'm bored" at least four times before 10am. The good news is you don't need a fancy STEM kit from The Warehouse or a Pinterest-worthy sensory bin to fix it. Most of what you need is already sitting in your pantry or recycling bin.

We pulled together fifteen experiments that are genuinely easy, genuinely fun, and don't require a chemistry degree to explain. A few of them will make a mess, so maybe don't attempt the volcano on the good tablecloth.

The classics worth doing at least once

1. Baking soda volcano. Still the reigning champion of kids' science for a reason. Mould some playdough or damp sand around a small bottle, drop in baking soda, a squirt of dishwashing liquid and a few drops of red food colouring, then pour in vinegar and stand back. The fizz is an acid and base reacting to make carbon dioxide, which is a fancy way of saying "instant lava."

2. Rainbow milk magic. Pour full cream milk into a shallow dish, add a few drops of food colouring, then touch the surface with a cotton bud dipped in dishwashing liquid. The colours take off in every direction because the detergent is breaking down the fat in the milk. Oddly mesmerising for adults too.

3. Balloon rocket race. Thread string through a straw, tie it tight between two chairs, then tape a blown up balloon to the straw and let it go. If you've got more than one child, let them each build their own and race them. Simple demonstration of Newton's third law, though nobody needs to say that part out loud for it to be fun.

The ones that buy you a bit more time

4. Homemade slime. Half a cup of PVA glue, half a teaspoon of baking soda, a splash of contact lens solution and some food colouring. Knead it until it stops being sticky and starts being satisfying. This one will occupy them for a solid twenty minutes, partly because the texture is genuinely addictive.

5. Walking water rainbow. Line up a few glasses, alternating full ones with empty ones, and fold paper towel strips between each. Add colouring to the full glasses and leave it overnight. By morning the colour has "walked" into the empty glasses through the paper towel, which is capillary action doing its thing while everyone's asleep.

6. Crystal growing. Dissolve as much salt as you can into hot water, hang a piece of string in it, and check back over a few days. It's slow, which is actually the point. It teaches a bit of patience alongside the science, and the payoff crystals are a nice reward for waiting.

The quick ones for when you need five minutes of peace

7. Floating egg challenge. Drop an egg into a glass of plain water, then stir in salt gradually until it floats. Density in action, and a good one for asking "why do you think that happened?" before explaining it yourself.

8. Dancing raisins. Raisins in a glass of sparkling water bob up and down as carbon dioxide bubbles cling to them, lift them, then pop. Genuinely odd to watch and takes about two minutes to set up.

9. Pepper and soap trick. Sprinkle pepper across a bowl of water, then touch the middle with a soapy finger. The pepper shoots to the edges instantly because the soap changes the water's surface tension. Kids tend to want to do this one about six times in a row.

For the ones who want a proper project

10. Invisible ink messages. Write a secret message in lemon juice with a cotton bud, let it dry, then warm the paper gently with a hair dryer (or an adult with a cool iron) to reveal it. Great for a rainy afternoon and doubles as an excuse to write each other notes.

11. Homemade lava lamp. Oil, water, food colouring and half an effervescent tablet in a bottle. Oil and water won't mix, and the tablet keeps the bubbles coming for ages.