Electric Charge Essay, Research Paper

In some Greek experiments, objects attracted each other after rubbing. Other experiments produced objects that pushed away, or repelled, each other. The evidence showed that electric force made matter either attract or repel other matter.

Electric force is caused by electric charge. Electric charge is a property of the bits of matter within atoms. Electric force can cause matter to attract or repel because there are two kinds of charge positive and negative charge.

The effects of electric force can be summarized as the law of electric charge: Pieces of matter with the same kind of charge repel each other. Pieces of matter with the same kind of charge attract each other. 2 objects with a positive charge repel each other, as do 2 objects with a negative charge.

Most objects are made of matter with equal amounts of positive and negative charge. Objects with the same # of positive and negative charges are electrically balanced, or neutral. Electric force is observed only when the balance of charge on objects is disturbed.

An electric charge on an object that causes the object to attract or repel other objects is called static electricity. The adjective static describes something that does not move. Charges on an object are called static electricity to contrast then with the moving charges in an electric current.

How can you disturb the balance of charge on objects so they exert electric force? The easiest way is the same way the ancient Greeks did it by rubbing the 2 objects together. Rubbing neutral objects together allows charged pieces of matter to move from one object to another.

The invisible bits of negatively charged matter that move between objects are called electrons. The words electron, electricity, and electronics all come from the Greek word for amber elektron. The transfer of electrons explains the electric force that attracts the balloon to the wool. Rubbing the neutral balloon with the wool cloth allows some electrons to leave the wool and stick to the balloon.

Neutral objects, like the balloon and the wool, become positively or negatively charged when their charges are disturbed. When an object becomes charged, no new charge is created; charge is simply moved around. This observation has been tested many times and is always true. It is stated a scientific law. The law of conservation of charge states all electric events occur by rearranging or moving charge. The law of conservation of charge holds true for all events, whether in objects as small as atoms or as large as stars.

A scientific model is used to explain the transfer of charge between objects. I.e. when you walk across a carpeted room, your shoes scuff against the carpet and pick up electrons. You become negatively charged, and the neutral carpet becomes positively charged. No charge was created, but both you and the carpet are charged.

Acquiring excess charges is as easy as walking across the carpet. Losing excess charges is just as easy. Since different types of charges attract, positive charges on one object can pull electrons off a nearby object very quickly. The rapid transfer of electrons is called an electric discharge.

The unit used to measure amount of charge is the coulomb, named after the French physicist Charles Coulomb. One coulomb is a very large amount of charge. I.e. a strong lightning bolt carries 10-20 coulombs of charge between a cloud and earth. Most charge transfers in the static electricity experiments you do are much smaller. The spark that jumps between your finger and a doorknob carries only about 1 millionth of a coulomb of charge.