WORKSHEET 12

Activity - Eggsperiment

Print and copy this worksheet for use in the classroom.

 
 
In this teacher demonstration, you will use an egg to investigate changes in air pressure.
Egg in Bottle Diagram

Equipment

  • hard boiled egg
  • matches
  • paper towel
  • small jar or bottle with an opening large enough to let an egg almost pass through.
 

Safety

This should be done as a demonstration activity.
 

Procedure

  1. Peel the hard boiled egg
  2. Ignite a small piece of paper and drop it into the bottle
  3. Immediately place the egg gently on the opening of the bottle, small end first. The egg may "dance" and wobble on top of the opening.
  4. Wait until the egg is drawn (really, pushed) into the jar.
  5. Ask students to suggest ways of getting the egg out of the bottle.
  6. Hold the bottle upside down with the small end of the egg in the bottle neck.
  7. Tilt the bottle down until there is a small opening between the neck of the bottle and the egg.
  8. Blow hard into the bottle making a closed seal with your mouth. Before you remove your mouth, tilt the bottle upside down.

 

Questions

Answer the following questions in the spaces provided.

 

 
  1. Why did the egg drop into the bottle?









  2. Why did blowing into the bottle remove the egg?
 


Explanation

  As the air was heated, it began to expand. Some of the air escaped causing the egg to wobble. When the flames went out, the air began to cool and contract. The egg sealed the bottle. Air pressure inside the bottle dropped below that of air outside the bottle. The greater air pressure on the outside pushed the egg into the bottle, equalising the air pressure inside and outside the bottle.
 

 

This activity is courtesy of
the Cooperative Research Centre for Southern Hemisphere Meteorology