Walking Water

This is experiment is magical! Your child will be blown away when they see what happens in the empty cup. This project takes a little bit of patience, but the lesson will be well worth the wait!

Disclaimer: This project does need a paper towel. I am aware we are in a quarantine and that paper towels are hard to come by these days, but only a sliver of one sheet of a paper towel is needed. I will include links to paper towels that are in stock.

Materials

• 1/3 of a piece of paper towel

  • here are some that are still in stock - option 1, option 2, option 3, option 4

• 3 glass cups around the same size

• water

• yellow food coloring

• blue food coloring

Directions

1. Place 3 glass cups next to each other in a row

2. Fill the two outer cups with about 2-3 inches of water, leaving the middle cup completely empty

3. Put 2 drops of blue food coloring in the first cup and mix

4. Put 2 drops of yellow food coloring in the last cup and mix

5. Take a paper towel and cut 2 slivers (about 2 inches wide) 

6. Fold the paper towel in half lengthwise and put one end of the paper towel in the cup with the blue water and the other end of the paper towel in the empty cup

7. Fold the other paper towel in half lengthwise and put one end of the paper towel in the cup with the yellow water and the other end in the empty cup

8. Leave the cups over night and watch what happens in the morning!!

9. You should find the middle cup filled with green water!

Questions you can ask your kids:

What do you think will happen to the water?

What is happening now?

Why do you think the colors are changing?

Why might the water be able to move up against gravity like that?

How it works:

The water moves up the paper towels through a process called capillary action. The paper towel is made from fibers and the water is able to travel through the gaps in the fibers. The gaps in the paper towel act like capillary tubes and pull the water upward. This is what helps water climb from a plant’s roots to the leaves at the top of the plant or tree.

The water is able to move upward against gravity because of the attractive forces between the water and the fibers in the paper towel.

You can also try this rainbow walking water.