The Laws of Electrostatics Charges
Like Charges Repel
Unlike Charges Attract
Conservation of Charge:
This law is really another way to state the Law of Conservation of Energy.
During the process of charging, the total number of charges exchanged between objects remains constant.
The Algebraic sum of all electrostatic charges produced during a charging process is always zero.
Neutralizing a Charged Object
Neutralizing means removing a charge from a charged object. This can happen in several different ways.
1. Charge "Leak Off":
Charged objects can hold on to their charge for a limited period of time only. After a while their charge "leaks off". The loss of charge may be due to the presence of another nearby charged object or to the presence of humidity (water vapour) around the charged object. Water is a polar molecule (the hydrogen side is slightly more positive than the oxygen side of the molecule). Because of this polarity, water can neutralize either type of charge.
Connecting a charged object to the ground by means of a conductor, will neutralize the charged object.
The ground (the earth) is so big that can be either a reservoir of electrons or a receptor of electrons. Positively charged object will be neutralized when grounded because electrons will flow from the Earth (the ground) into the object. Negatively charged objects will be neutralized when grounded because electrons will flow from the charged objects into the ground (the earth).