Walking Water

Walking Water

Water | 15 minutes + check up later on

In this activity, students will see water move from one cup to another with no human help!

Do this activity first. It takes a little time to get results.

Materials Needed

Per group:

  • Three clear, empty glasses or jars

  • Enough water to fill ⅔ of two glasses

  • 2 paper towels

To share:

  • Food coloring

  • Stirring devices (stick, spoon, etc.)

Optional:

  • Flowers with white petals

Steps:

  1. Choose two different colors of food coloring.  

  2. Fill two glasses or jars about ⅔ full of water, and add a few drops of food coloring.  Stir the water briefly.

  3. Place the empty glass between and close to the other two.

  4. Fold a paper towel into quarters lengthwise.  Place one end of the folded paper towel into the empty glass and the other into one of the glasses of colored water.  Fold the other towel in the same way and place it into the empty glass and the remaining glass of colored water.

  5. Observe for a few minutes and then set aside.

  6. Check on it every 20 minutes or so.

Explanation:

When you put your paper towel in between the cups, it starts getting wet. After a few minutes, the middle jar starts to get liquid in it. It keeps filling up until all three jars are at equal levels. This is because of a process called capillary action. That is when the water molecules travel up through the paper towel and into the glass by “sticking” to each other and filling in the gaps in the paper towel.

Real World:

This is the same way that plants suck water up through their roots and into their petals!

It is also why paper towels and napkins are great for cleaning up spills.

Optional

Try it!

What happens when you fill up one glass and make a paper towel bridge to two or three empty glasses?

Try putting a white flower in a cup with colored water. Check on it in a few hours or the next day and see what happened.