Wednesday, May 2, 2012
Objects can also charge without any contact. When dust builds up on a computer screen, and the screen is turned on, the dust gathers a charge. When a neutral dust particle comes near the screen, the screen induces an opposite charge on the near side of the dust particle, attracting it to the screen.
Electricity is basically electrons moving quickly from atom to atom. An insulator is a substance in which the electrical charge cannot move to another object. Substances such as plastic, rubber, and glass are insulators. A conductor is on object through which an electrical charge passes easily. Most metals are good conductors. A semiconductor allows the electricity to travel through them, but not as easily.