Hair-raising Science (Static Electricity)

  • Have you ever walked across a carpet and gotten a shock when you touched a doorknob? Or perhaps after pulling a sweater over your head, you found that your hair just sort of stuck up in the air and wouldn't go down? Don't worry, it's not alien forces or magical powers, you've just entered "the static zone"! Static electricity is more than a nuisance, it's a force of nature that people have been trying to figure out for almost 3000 years.

    Here's what you'll need:

    • A balloon
    • A clean head of hair
    • Some tiny bits of torn up newspaper
    • A sheet of aluminum foil about 1 foot long
    • A wool sweater or sock
    • A sheet of wax paper about 1 foot long
    • A sheet of cellophane wrap about 1 foot long

     Begin by blowing up the balloon and rubbing it on your head.
    1. What happens to your hair?

     

     Now lay the bits of paper out on a table in front of you. Bring the balloon near, but don't actually touch the paper.
    2.What happens?

     

    If you said the paper jumped up to the balloon, congratulations! You've just discovered static cling! When you rubbed the balloon on your head, you removed some electrons from you hair and stuck them on the balloon. It's these electrons that caused the paper to be attracted.

    Okay, so here's the challenge: Do all substances "give up" electrons when they are rubbed against the balloon?

    • Begin by predicting which of the four materials (wool, cellophane, wax paper or aluminum foil) might cause an electron build-up when they are rubbed against the balloon. Make sure you explain WHY you think this might happen.

    Prediction yes no Why? Result of test
    wool        
    cellophane        
    wax paper        
    aluminum foil        

    After you've made your predictions, start rubbing the balloon with each material and test it with the paper bits. Do all materials create static cling?  List your findings in the chart above under "result of test".

    Also, if you're in the mood to experiment, try rubbing the balloon on some other stuff like you dog, the sheets on your bed, and your pajamas. So get rubbing, and may the "static force" be with you!