Do the preparation exercise first. Then read the text and do the other exercises.
Science experiment: Walking water
Try this science experiment to make water 'walk'. You can even make rainbow colours!
Before you start
Ask an adult if you can do the experiment.
What you need
- three empty glasses
- food colouring
- paper towels
How to do it
- First put a few drops of yellow food colouring in a glass.
- Then put a few drops of blue food colouring in another glass.
- Next fill the glasses with water.
- Put an empty glass in the middle.
- Fold a paper towel to make a long thin piece.
- Put one end in the yellow water and the other in the empty glass.
- Then fold another paper towel.
- Put one end in the blue water and the other in the empty glass.
- Wait for an hour or two.
- Finally look at the glass in the middle. What can you see?
How does it work?
This experiment works because of something called 'capillary action'. Usually water only flows down, because of gravity. But as the spaces between the fibres of the paper towel are so small, the water actually moves up, against gravity!
Did you know?
Trees also use capillary action. Water moves up the roots to feed the whole tree!
Did you see green water in the middle glass? That's because yellow and blue make green. You can do the experiment using different colours. Try using seven glasses to make a 'rainbow'!
Do you like science? Do you know any other experiments? What experiments would you like to do? Tell us about it!