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Top 10 fun and easy science experiments

Simple science

Make the most of Science Week with these tried-and-tested kids’ science experiments you can easily try at home. From a DIY lava lamp to colour mixing, there are ideas suitable for pre-schoolers and toddlers - and they support what they’ll be learning at school.
  • 30 minutes
  • Kids of all ages

1. Do oil and water mix? A cool marbling experiment

What you’ll need: a clear tub or shallow dish, vegetable or baby oil, food colouring (2 colours), a paintbrush

What to do: 

1. Help your child to fill a clear tub or shallow dish with about 1cm of oil.

2. Add drops of food colouring.

3. The oil and food colouring won’t mix so your child can swirl them with a paintbrush to create an amazing marble effect.

2. Does it sink or float? Play a fun game

What you’ll need: A bowl of water, toys and items that you don’t mind getting wet, a towel

What to do:

1. Fill a bowl with water.

2. Ask your little one to guess whether they think an object will sink or float.

3. Encourage them to drop the object into the water and see what happens.

4. Older children could record the results by drawing a table.

3. How do you make your own lava lamp? Try this easy idea

What you’ll need: A tall glass, water, vegetable oil, food colouring, table salt

What to do:

1. Help your child to pour water into a glass until it’s two-thirds full.

2. Ask them to drop a little food colouring into the glass. They don’t need lots – if they keep it light, they’ll see the lava better.

3. Help them to top up the glass with vegetable oil, leaving about an inch at the top so that it doesn’t overflow.

4. One by one, ask them to add spoons of salt (you’ll need quite a bit but add it slowly), and watch the lava effect take shape!

4. How do plants grow? Plant a cress seed and see!

What you’ll need: cotton wool, a plate, cress seeds, water

What to do:

1. Give your child cotton wool to place on a plate. Ask them to pour water over the cotton wool (carefully!), so it’s damp but not soaking wet.

2. Now they can sprinkle a small handful of cress seeds over the cotton wool.

3. Place the seeds on a windowsill, or a place where they will get sunlight.

4. Remind them to check whether they need more water each day by touching the cotton wool to see if it’s still damp. If it’s dry, add a little bit of water until it’s damp again.

5. After ten days, they’ll have cress they can eat! Until then, they can keep an eye on the cress and watch it sprout and grow. What do they think would happen if it didn’t have daylight, or too little or too much water?

5. How do you make new colours? Try mixing with paint

What you’ll need: red, blue and yellow paints, a paintbrush, paper

What to do:

Ask your child to try mixing two paint colours together. What colour do they get when they mix red and yellow? What other colours can they make by mixing the primary colours together? Ask them to make a painting with their new colours.

6. Can water walk? A colour mixing experiment

What you’ll need: 6 clear cups or jam jars, water, red, yellow and blue food colouring, whole sheet of kitchen roll, scissors

What to do:

1. Put water in the 3 of the cups (fill them almost to the top). Put 5 teaspoons of red food colouring in the water of one cup, then do the same with the yellow and then the blue in the other two cups.

2. Position the cups in a circle, alternating the empty ones with those filed with water.

3. Use a whole sheet of kitchen roll, fold in half twice length ways and then again in half. Then trim so it’s long enough to curve from one cup to another (but not too long!). Repeat until you have 6 strips of kitchen roll.

4. Now position the kitchen roll strips in the cups as follows:

  • One in the red cup leading to the empty cup next to it.
  • One in that empty cup leading to the yellow cup.
  • One in the yellow cup leading to the empty cup next to it.
  • One in that empty cup leading to the blue cup.
  • One in the blue cup leading to the empty cup next to it.
  • One in that empty cup leading to the red cup you started with.
  1. Be amazed as the water starts to walk! In the next few minutes, you’ll see it travel up the kitchen roll and down into the cup where the colours will mix.

7. How much does it rain where I live? Try this measuring idea

What you’ll need: a plastic bottle, stones, a marker pen, a ruler

What to do:

1. Cut off the top half of a plastic bottle.

2. Take the plastic bottle outside and find a good space for it. Your child can pop some stones in it, so it doesn’t blow over.

3. Leave it outside and check it throughout the day (or over a few days).

4. When rain has fallen, draw a line on the side to see how much rainwater you have collected. You could compare how much rain falls each day for a week. Draw a new line each day.

8. Where do animals live? Group creatures by their habitat

You’ll need: toy animals 

What to do: 

Choose an animal and ask your child to guess where it lives – in water, on land, or both? They can talk about animals they have seen (like ducks), or how about a tiger, or a crocodile? They can think about how the animal looks to help them guess; for example, a fish has fins but no feet. Now, your child can put the animals into groups. Younger children could group them by size or colour.

9. Is black ink really black? Discover the secret colours in felt tips

You’ll need: 5 white paper coffee filters, felt-tip pens (including black), water, 5 small jars

What to do:

1. Draw a line around the middle of each coffee filter with a different colour felt-tip pen.

2. Pour a small amount of water into each jar.

3. Stand the bottom of the filters in the water.

4. Watch as the water travels up the filter and separates the colours inside the felt tip!

5. Which felt tips are made of the most different colours? Your little one should find that black and brown reveal the most.

10. Why does it rain? Shaving foam cloud experiment

You’ll need: a pint glass, water, shaving foam and blue food colouring

What to do:

1. Fill the glass ¾ full of water. Now ask your child to create a cloud on top with a good squirt of shaving foam.

2. Fill your cloud with rain by adding a few drops of food colouring. As the cloud fills up and gets heavier, rain will fall down, just like a real cloud!