Mary Snyder, age 10, of Columbia, Pennsylvania, for her questions
What is static electricity?
With a little help from La, static electricity is always willing to perform parlor tricks. On a cold. dry day, it may even perform all by itself. If you stroke a cat on such a day, her fur may stand on end. If you brush your hair, it may crackle and fly after the brush, Your feet make crackling noises as you walk over a thick rug. If you then go to turn on an electric light, a spark may fly from your hand to the switch.
All these tricks are done by static electricity. In fact, the very name electricity came from such a trick. Certain substances are more likely to show static electricity than others. The ancient Greeks found that by rubbing a piece of amber with cloth, bits of lint and straw would fly towards it and cling. Their word for amber was elektron. Centuries later, when we learned more of this magic force, we named it electricity in honor of that old piece of amber.
A simple parlor trick will help you to see how static electricity works, You will need a hard rubber comb, a piece of woolen cloth and a small ball of crumpled paper hanging from a thread. Rub the comb with the wool and hold it near the paper ball. The paper ball will be drawn towards the comb. It will touch and bounce back. This is static electricity at work,
The problem is solved when we remember that everything is made of atoms and atoms are made from particles of electricity. The proton particles in the nucleus of the atom are charges of positive electricity. The electrons which orbit the nucleus are particles of negative electricity. Each normal atom has an equal number of protons and electrons, which means it has equal charges of positive and negative electricity,
Two charges of positive electricity repel each other, as do two charges of negative electricity. But a charge of positive and. a charge of negative electricity attract each other. The equal charges of positive and negative in a normal atom keep it electrically balanced.
The positive protons do not leave the atom. But the orbiting electrons tend to fly off at the slightest excuse. When you rubbed the comb, you created friction. The friction made electrons fly from the wool into the comb. The comb gained an extra supply of electrons which gave it a charge of electricity. A charge of electricity has a strong impulse to even out, or discharge itself and get things back to normal.
When the rubbed comb name near the paper ball, it drove the electrons in the paper molecules further away than the protons. Being a negative charge, it attracted the protons, pulled them and the ball with them until the two objects touched. Then some of the surplus electrons hopped from the comb into the paper. The ball, like the comb, now had an extra charge of negative electricity. The ball anal the comb now repel each other. The ball bounced back.
Static electricity is a give and take of electrons between objects, It is useful for parlor games and for understanding the basic nature of electricity, When properly disciplined, the same little electrons which make static electricity can be made to give us an electric current.