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Try This: Zap! by J. Elizabeth Mills

Have you ever pulled on a sweater in winter and then touched a doorknob? Did you feel a jolt in your fingertips? Or have you ever touched someone's hand and felt a zap? That's static electricity.

FUN FACT

Big Bolts

One bolt of lightning can measure 3 million volts in just one second. A spark of static electricity can equal 3,000 volts.

QUESTION

What causes static electricity?

WHAT YOU NEED

• Socks

• Carpet

• Metal doorknob

• Balloon

WHAT TO DO

• Put on the socks.

• Shuffle your feet across the carpet for a few seconds.

• Touch a metal doorknob. What happens? Make sure the doorknob is the first thing you touch after you shuffle your feet.

• Blow up the balloon and tie it.

• Rub the balloon on your hair and then pull it away slowly. What happens to your hair?

• Now stick the balloon to a nearby wall and let go. Does it stick to the wall?

static electricity: electricity caused by rubbing two objects together.

FUN FACT

Bird on a Wire

Have you ever looked up and seen a bird sitting on a telephone wire? Ever wonder how the bird can safely sit on a wire that conducts electricity? As long as no part of the bird is touching the ground, the current passes right through the bird without hurting it. You, on the other hand, should never go near a power line.

WHAT'S HAPPENING

When you shuffle your feet on a carpet and rub the balloon on your hair, you're putting something on it called negative charges. Charges can be positive or negative. Like a magnet, two positive charges repel each other, but a positive charge and a negative charge attract each other. You build up these charges as long as you don't touch anything. Once you do, you release the charges onto another surface. And that's what causes the zap. When you then placed the balloon against the wall, the negative charges in the balloon were attracted to the positive charges on the wall. So they stuck together!

Static electricity usually isn't dangerous. It's a tiny charge. But there are times when it's a problem. At gas stations, there sometimes are signs telling drivers to touch their cars before filling their gas tanks. A driver can build up static electricity from the seat in his car and then release those charges on the gasoline hose. This can cause a fire. It is important to always be safe when using electricity.