Electric charge can be either positive or negative. Protons have a positive charge equal in magnitude but opposite in sign to the negative charge of electrons. Opposite charges attract each other, while like charges repel. In any system, the net charge is conserved. For example, a neutral hydrogen atom has a net charge of 0. If the electron becomes separated from the atom, the hydrogen ion now has a positive charge of +1. However, the system still includes the -1 charge of the electron, so the net charge remains 0.
