SCIENCE CONCEPTS: HANDS –ON ACTIVITY # 2

Sketch:

Materials:

1. 2 drinking cups
2. 2shiny pennies
3. modeling clay, 2 grape-sized pieces

 State/Goal(s)/Objectives:  11.a.1a- Describe an observed event

Safety Considerations:  Use trays to avoid spills.

Math Connection: none

Science Process Skills:  observing and communicating

Procedure:

1. Stick the pieces of clay in the inside bottom of each cup.
2. Press a penny in the clay so that it is in the very center of the cup with water.
3. Fill one cup with water.
4. Place both cups on the edge of a table.  The cups must be side by side and even with the edge of the table. 
5. Stand close to the table.
6. Take some steps backward while observing the pennies in the cups.
7. Stop when you can no longer see the pennies in either cup.

Explanation:

            The penny in the cup filled with air disappears from view first, while you can still see the penny in the cup filled with water.  Because you see the penny in the water at a greater distance because light enters the cup, reflects from the penny, hits the surface of the water, and is bent at an angle (refracted) toward your eye.  The water is thicker than the air and thicker materials refract the light more.  A change in the thickness of the earth’s atmosphere due to pollution increases the refraction of light. 

Source: 

VanCleave, Janice. (1991). Astronomy for every kid: 101 easy experiments that really work.  New York:  John Wiley & Sons, Inc.