Static Electricity

Static electricity has at least two similarities to magnetism: the seemingly magical attraction and repulsion of one object for another, and the attraction of people of all ages. Another common thread between the two subjects is that our understanding of both of them is still based largely on this theory. Through observation and experimentation, logical explanations of the phenomena have been developed.

An understanding of static electricity must begin with the concept that all matter is composed of atoms, and all atoms are composed of subatomic particles among, which are the charged particles known as electrons and protons. Protons carry a positive charge (+), and electrons carry a negative charge (-). Ordinarily every object carries equal numbers of protons and electrons and is said to have a neutral charge.

When two different materials come into close contact -- for example, felt rubbing against a balloon, or two air masses in a storm cloud -- electrons may be moved from one material to the other. When this happens, one material ends up with an excess amount of electrons and becomes positively charged. This growing of imbalanced charges on an object results in the phenomena we call static electricity.

Materials that carry imbalances of opposite charge will attract each other and cling together. Materials that carry imbalances of like charge will repel each other. When an object carrying a large accumulation of positive charge or negative charge comes in contact with another object carrying the opposite charge, a spark may jump across the space between them. This results in both the enormously powerful discharges of lightning, and the small yet stimulating shocks we receive when touching something after shuffling across a carpet in our stocking feet.

Because wool cloth is a material that is waiting to give up electrons, it is used in many activities to produce an accumulation of negative charge on an otherwise neutral object. Human hair is another common material that readily gives up electrons.

A material such as rubber is known as an electrical insulator. Accumulations of charge will not move across the surface of a rubber object easily. When one part of a balloon is rubbed with wool, the wool gives up electrons, making that part of the balloon negatively charged even though the remainder of the balloon will remain neutrally charged.

When a charged object such as a piece of Styrofoam, the Styrofoam is said to become a negatively charged induction and may jump toward the charged balloon. An object charged by the induction does not actually have to lose or gain electrons. A negatively charged by induction balloon taken near a negatively charged piece of Styrofoam repels the electrons on the surface of the Styrofoam. The repelled electrons move as far away from the balloon as possible. This leaves the near end of the Styrofoam with an imbalance of positive charge and results in the attraction of the Styrofoam for the balloon.