One of the basic constituents of matter. Modern theory describes an electron as a wave-particle, which behaves unlike everyday waves or particles. Below is a list of the basic properties of the electron.

The electron is a member of the lepton family of particles, and one of the three basic particles that form atoms. It is typically found in clouds surrounding atomic nuclei, but is relatively easy to separate from an atom into electron beams, or just into electric current. Electrons are fundamental particles, that is, they are not composed of anything else.

The electron is the primary conductor of electric charge, since it is much more free to move about matter than its counterpart, the proton, which is far heavier.

It has a charge of -1 elementary charges, and its antiparticle, the positron, has a charge of 1. In coulombs, this charge is 1.60217733(49)x10-19

An electron's rest mass is 1/1804 of that of a proton, or 9.1093897x10-31 kg

The electron-volt, a unit of energy, is defined as the energy gained by one electron in going through an electric potential of 1 volt. It is a very small unit, with one mega-electronvolt(MeV) being equal to 1.602x10-13 joules. The rest mass of the electron, measured in electron volts (Thanks to Einstein's little formula) is 0.5109906 MeV.

The radius of an electron is 2.81794092x10-15 m, if considered as a particle, though modern theory sees an electron as a wavepacket, not as a particle. The wavelike nature of the electron is utilized in things like electron microscopes and many puzzling quantum mechanics experiments