Minds on Science Gazette

Volume 9

Planning Activity: Physical Science

Designing Units & Courses

 

In this activity, students observe a teacher demonstration (a discrepant event), and then theorize possible explanations for the event.

Objectives

• To describe the effects of air pressure on an object
• To explain how an egg is able to be forced into a bottle

Concepts

• Air pressures
• Molecules
• Heat
• Cooling

Materials

Glass quart milk bottle, hard boiled egg with shell removed, match, crumpled-up piece of paper

Procedure

1. Tell the students that you are going to do a demonstration. You are going to try to put an egg (show it to them) into a bottle (show them) with touching or forcing the egg in the bottle. Ask them if they have any ideas about how this could be accomplished. Record their ideas.

2. Carefully drop a small wad of burning paper into the milk bottle. Just before the flame goes out, place the egg, the smaller end down, in the opening of the bottle. Have the students watch the egg squeeze into the bottle.

3. Arrange the students in pairs to make a diagram and write explanations for what they think caused the egg to go into the bottle.

4. After ten minutes, have students explain their ideas to the whole class.

Applications to Science Teaching

1. Could this "activity" be used as a performance assessment? How would you set it up, and what criteria would you use to "evaluate" the students performance?

2. What are some additional activities that you could use to help students understand air pressure, or other properties of air?

3. What cognition does this activity help students understand?