Activity

Static electricity with a balloon

Summary
Use a balloon to make static electricity. Optional: discuss as a force that acts at a distance.
Science content
Physics: Electricity, Electromagnetism (7)
Lessons activity is in
Materials
  • balloon
  • head of hair
  • empty tin can
  • steady, thin stream of water from a tap
Procedure

Inflate the balloon and tie it off.

1. Rub it in your hair to make a charge difference between the balloon and your hair. (Electrons are transferred from your hair to the balloon.)
Hold the balloon (negatively charged) just above your head so your hair (positively charged) will be attracted to it and stand up on end.

2. Lay a tin can on the floor on its side. Rub the balloon in your hair to charge it, then hold it close to the tin can. The can will start to roll towards the balloon without touching it.
The negatively charged balloon repels the electrons of the can so that a positive charge is near the balloon. The positive charge is attracted by the negative charge of the balloon.
http://www.sciencebob.com/experiments/staticroll.php
http://www.exploratorium.edu/science_explorer/roller.html

3. Bring the charged balloon near to a thin stream of water from a tap. The water will bend towards the balloon, as the charged molecules in the water are attracted to the negatively charged balloon.

4. Experiment with what else the charged balloon will stick to: sweater and clothing, styrofoam, the wall...
Set up as a free play activity where students investigate in their own way. They should take notes on what they find, to refer to when the group comes together to discuss what they found.

Notes

Carnarvon added the balloon lifting hair (without touching it) by electrostatic force, as a force that acts at a distance. Done after magnet stations.

Grades taught
Gr K
Gr 1
Gr 2
Gr 3
Gr 4
Gr 5
Teaching site
Carnarvon Elementary
Gordon Elementary Science Club