PRESENTED BY: Cindy Larson-Miller

BORROWED FROM: Newton's Apple

SUBJECT AREAS: Physical Science, Chemistry

CONCEPTS COVERED: Surface tension

MATERIALS:

Picture of a small fish

Pan of water

Vegetable oil or detergent

PROCEDURE:

1. Trace a picture of a fish on a piece of paper and cut it out. Cut a small hole in the center of the fish.

2. Place the paper fish in the pan of water.

3. Drop a tiny amount of oil or detergent into the hole in the fish.

QUESTIONS:

1. Ask the students to predict what will happen.

2. What happened?

3. Why doesn't the fish move at first?

4. Why does the fish move after the oil is placed on it?

5. What is surface tension?

6. Is the surface tension of the water increased or decreased by the oil?

7. Which has a greater surface tension, the water or the oil?

RATIONALE:

All liquids have a certain amount of surface tension, a property that causes a liquid surface to behave like an elastic skin. The vegetable oil or detergent decreases the water's surface tension. If different parts of the fish have contact with different surface tensions, the fish will be propelled.

APPLICATIONS: To be added by user