One of the four four
forces of nature. Electromagnetism acts between all particles possessed of electric charge: e.g.,
electrons,
protons, atomic ions. It is manifested in two interconnected forces, those of electricity and magnetism. Both have polarities as well as magnitudes. In electric charges, the polarities are distinguished by sign, positive and negative. In magnetism, the polarities are denoted either north or south. In both cases, like polarities repel whilst unlike polarities attract. The
virtual particles which carry the electromagnetic force are virtual
photons.
