A stable subatomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids.

Electrons belong to a class of particles called leptons.

The electron’s mass is about 9 × 10⁻²⁸g, 1836 times less than that of the proton. Electrons orbit the positively charged nuclei of atoms and are responsible for binding atoms together in molecules, as well as for the electrical, thermal, optical and magnetic properties of solids.

Electric currents in metals and in semiconductors consist of a flow of electrons, and light, radio waves, X-rays and much heat radiation are all produced by accelerating and decelerating electrons.