Publisher Summary Electric charge is one of the fundamental characteristics of matter. An object is given an electrical charge by changing the number of electrons. The addition of electrons results in a negative charge whereas the removal of the electrons results in a positive charge. The electron and the proton carry charges of opposite sign but of exactly equal magnitude. The rules regarding the attraction or repulsion of charged objects are like charges repel, and unlike charges attract. This chapter explains the basic properties of conductors and insulators in terms of electron behavior and the law of electric charge conservation. The term “electricfield” describes the condition that an electric charge sets up in space to which another charge responds. Electric field lines begin on positive charges and end on negative charges. The electric field between a pair of uniformly and oppositely charged parallel plates is uniform—that is, it has the same direction and magnitude at all points. The electric field strength is measured in volts/meter. The strength of the electric field between a pair of uniformly charged parallel plates is equal to the voltage across the plates divided by the separation of the plates. The direction of current flow is opposite to the direction of the net flow of electrons.