Electrostatics

Electrostatics is the study of stationary electric charges and their behavior. Charge is a property, and objects can be negatively or positively charged. More protons than electrons will yield a positive net charge, while more electrons than protons will yield a negative net charge. If there is no net charge, the subject is neutral. Both electrons and protons have equal and opposite elementary charges of ± 1.602E-19 Coulombs. Like charges repel while opposites attract.

Since charges can repel or attract one another, that means that they must experience some force. Coulomb's Law gives the magnitude of force between two particle charges:

Polarization

Polarization is the phenomena that occurs when positive and negative charges are separated to opposite sides of a single object. Consider the following example:

A positively charged rod is brought near a neutral sphere. Since the rod is positively charged, it has an excess of protons. These protons will attract the electrons inside of the neutral sphere towards the side of the sphere closer to the rod. Simultaneously, the excess protons in the rod will repel the protons in the sphere to the furthest side of the sphere. The sphere is now said to be polarized because all of the protons reside on one side of the sphere while all of the electrons reside on the other. Polarization is the key to electrical induction which will be discussed next.

Induction

Electrical induction is a method in which a neutral object is given charge. It is best explained by the graphic below.

Electrical induction only works for a special class of materials known as conductors. Electrons can move freely in conductors while they cannot in insulators. This is why electricity cannot move through materials such as plastic or rubber, both which are insulators. On the other hand, electricity can pass very well through metals like copper, which is a conductor.