How to Teach with a Van De Graaff Generator

A Van de Graaff generator is designed to generate static electricity--the same phenomenon that can give you a nasty shock on a shag carpet and make your hair stand on end. It is also a wonderful tool for teaching science, especially to children.

Difficulty: Moderately Easy

Instructions

1. Preface your lesson with an explanation about electrons and protons, electrical charges and how opposites attract. Rub an inflated balloon against the shaggiest hair in the class--perhaps your own--and place it against the wall or drapery. The balloon should stick: its surface steals electrons from the hair, attracting it to the wall's protons.

2. Have yourself or a student stand on top of a non-conductive platform before the generator has been turned on--a milk crate could be ideal. Place a hand on the crown of the generator. The generator shouldn't be switched on until everyone is in position.

3. Turn on the generator. The student's hair will stand on end and in every direction. Explain that this is a case of the generator transmitting excess electrons into the student. Opposites attract, and likes repel, so these electrons, all negatively charged, attempt to get as far away from each other as they can.

4. Place styrofoam peanuts into the the student's hand, and turn on the generator. In addition to their hair spiking in all directions, the peanuts will actually fly out of their hands. Like the electron-charged hair, they are attempting to flee each other's presence as quickly as possible.

5. Leave with a bang. Ask your students if they want to shadowbox with the generator--cocky male students might be more willing to perform this task. Thrusting your fist close to the generator will elicit a discharge--this will hurt, slightly. And yet, you may be surprised how enthusiastic your students become about this exercise.

Tips & Warnings

• You can also place a box of styrofoam peanuts on the generator itself. The box will erupt with peanuts flying in all directions. The only downside is the clean up afterwards.
• The sparks are best seen in the dark.
• If the generator is on, but no one is using it, be careful. The building charge will eventually discharge on its own, perhaps leaping a few feet across the room to do so.