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Saturday, March 3, 2012

Elementary Electricity--Tricky Science Activities

Turn a plastic comb into a "magic wand" and explore the science of static electricity with these simple activities.

Here's What You Need:
a plastic comb
a piece of wool fabric (other materials work, too)
a teaspoon of salt
a teaspoon of ground black pepper

Here's What You Do:

Have your little one mix a spoonful of salt and a spoonful of pepper together in a separate bowl, or just on the table.

Rub the plastic comb vigorously with a piece of fabric; or your child can try rubbing the comb on the fabric of his or her clothing. Hold the comb about an inch above the salt/pepper combination.  The pepper will start to jump onto the comb!

*Variation:  Use small snippets of colored tissue paper instead of salt and pepper. The charged comb will lift the the tissue paper.

Why?  Every object is made up of atoms which contain electrons. Some electrons are negatively charged, some are positively charged, and some are neutral. Atoms usually have a balance of electrons. But when the comb is rubbed on the fabric, it becomes unbalanced with a negative charge.  When it is held above the salt and pepper, it is attracted to the positive charges in the pepper, (which is lighter than the salt)--and opposite charges attract, like magnets! The pepper or bits of tissue paper jump to the comb. 

Now bend a stream of water with your science magic!

Charge the comb by rubbing it vigorously on fabric, or combing it through clean hair at least ten times.  Turn on a faucet so there is a small stream of water, and hold the comb near the stream without touching it to the water. The negatively charged comb will pull the neutrally charged water toward it--the water appears to bend!

Rub a balloon on your head, and the same principle will make it stick to the wall, or your body!

1 comment:

  1. You always have such fun ideas. This one is no exception! My sister is looking for ideas to do with her students, so I'm passing along your blog that has provided so much inspiration for me!