Vicky Sambunaris, age 13, of Lancaster, Pa., for her question:
WHAT IS STATIC ELECTRICITY?
Electricity is a form of energy, and almost everything is basically electrical. All matter is made up of atoms, with each atom having one or more electrons and one or more protons. A proton is a positive particle of electricity, and an electron is a negative particle. If the atom gains some electrons, it becomes negatively charged; if it loses some, it becomes positively charged.
There are two kinds of electricity: current electricity and static electricity. Both are really the same although they act differently. Current electricity consists of moving electrons, and static electricity consists of ions or electrons that are not moving.
After walking across a rug on a very dry day, have you felt a shock as you touch a doorknob? The shock was caused by static electricity.
Static electricity is the form of energy that makes your hair crackle when you comb it. You can make static electricity by rubbing a comb on a piece of wool. The atoms in the wool lose some of their electrons and atoms in the comb gain them, making the comb negatively charged and the wool positively charged. Hold the comb near some small scraps of paper. You'll discover the comb attracts the paper, which has no charge.
A negative charge on a toy balloon can be obtained by rubbing it against your hair. The balloon will stick to a wall or the ceiling because the balloon is charged and the wall or ceiling is not.
An item doesn't always have the same charge when rubbed. If you rubbed a piece of glass with a silk scarf, for example, the silk would become negatively charged and the glass positively charged. But if you rubbed a piece of rubber with the silk, the .silk would become positively charged and the rubber negatively charged.
Static electricity, you have probably decided, has few uses. You are right. Current electricity, on the other hand, works for man.
Electric current in a wire works much as water in a hose. When you turn a hose on at its nozzle, the water will come out immediately. But individual molecules of water move only a short distance in the hose. Electric energy, on the other hand, works almost instantly, but free electrons in the wire move slowly.
Electrons are among the smallest known particles in the world. In a 60 watt light bulb, for example, about 3 billion electrons a second flow past any point in the wires to the bulb. That number is written out by putting 18 zeros behind a 3.
Electric energy travels through a wire almost as fast as the speed of light, which is 186,282 miles per second. When you talk on the telephone, electric energy allows you to hear a distant voice almost instantly.