Escaping Water

Objectives

• Observe the effects of capillary action using water and a paper towel wick.

Materials

• Per Demo or Student:
  a couple of paper towels
  2 glasses
  water

Key Questions

• Did the empty glass fill with water? How?
• How much water is still in the first glass?
• Does the paper towel look and feel different? Why do you think it does?
• Do you think this could be how a plant "drinks" water?

What To Do

1. Fill one glass with water and leave the second glass empty. Place them beside each other.
2. Twist the paper towels together so that they look like a rope. This will be the ‘wick’ that the water travels through.
3. Place one end of the ‘wick’ in the glass of water and the other end in the empty glass. It will take a few minutes, but you should start to see water dripping off the paper towel and into the empty glass.
4. Continue to check the demonstration throughout the day, or the next day, to see what happens. Eventually, both glasses should be about half-full.

Extensions

• Try adding food colouring to the water - it may be easier to keep track of the water's progress this way.
• Experiment with height. Elevate the full glass above the empty glass, or the other way around. Does it change the results?
• Try adding a third glass! Fill two glasses, and leave an empty glass between them, with two paper towel wicks from the full glasses sitting in the empty glass.
• Experiment with colour, too! Add separate food colouring to the glasses of water, then predict the colour of the water that fills the middle glass.