September 20, 2008


Electrical Charge

You have learned that electrons travel around the nucleus of an atom and are held in orbits by the attraction of the positive charge in the nucleus. When you force electron out of its orbit, then the electron’s action becomes what is known as electricity.
Electrons that are forced out of their orbits in some way will cause a lack of electrons in the material, which they leave and will cause an excess of electrons at the point where they come to rest. Materials having excess of electrons are called negative charge, while the materials lacking of electrons are called positive charge. When these charges exist and are not in motion, this is called as static electricity.

Two protons together or two electrons together signify like charges. Like charges resist when held closer together, and move away from each other. This movement is called repelling. The first law of electrostatic states that like charges repel each other. And the second law states that unlike charges attract each other. The amount of attracting or repelling force that acts between two electrically charged bodies depend on two factors: their charge and the distance between them.

A single electron has a charge too small for a practical use. Coulomb (C) is the unit adopted for measuring charges. The unit coulomb is named after Charles Coulomb. One coulomb is equal to 6, 250, 000, 000, 000, 000, 000 or 6.24x1018 electrons.