Preschool–Kindergarten
These simple activities demonstrate surface tension.
What You Need
- Index card
- Safety scissors
- Sink filled with water
- Glass half filled with water
- Liquid dishwashing detergent
- Ground pepper < !!! >
- Toothpicks
What to Do
From an index card, cut out a boat shape, like the one on this page. Make the boat about 2-1/2 inches long and 1-1/2 inches wide. Have your child place the boat gently on the water in the sink. Have him pour a little detergent at the notch end of the boat. Ask him to describe what happens. (Note: To repeat this experiment, you'll need to use fresh water to make the boat move.)
Next, sprinkle a little ground pepper on the water in the glass. Give your child a toothpick and tell him to dip it in the middle of the pepper. Ask him what happens. Then tell him to put a drop of the detergent on another toothpick and dip it into the pepper. Now what happens?
