Balloon-vacuum (Kenneth D. Howard)

Title

Balloon Vacuum

Author(s)

by Kenneth D. Howard

Principles Illustrated

Kinetic energy of molecules

Enthalpy/ Energy Transfer

Equilibrium of a system

Air pressure

The relationship between heat and the volume of gases

Vaporization of water and Condensation of water vapor

Standards

Energy is the property of many substances and is associated with heat

Heat moves in predictable ways, flowing from warmer objects to cooler ones until both reach the same

temperature.

Unbalanced forces will cause change in the direction of an object's motion

Questioning Script

Prior knowledge & experience:

All student are familiar with the properties of a balloon and how to blow it up.

Root question:

When I attach the balloon to the flask what will happen?

What is occurring when the balloon is drawn into the flask?

What is happening to the water vapor as the flask cools?

How much air is in the sealed flask?

What role does air on the outside play?

Target response:

Students will suggest the balloon will inflate.

Upon seeing the balloon going inside the students will respond that something is pulling

it inside the flask.

Common Misconceptions:

Most students will think the balloon will inflate since the flask was heated up,

they will think the hot air molecules will make the balloon expand.

The air in the flask is pulling the balloon down inside.

Photographs and Movies

References

http://www.mcrel.org/whelmers/index.asp