Commonly used unit of energy in atomic and nuclear physics. An electron volt is the kinetic energy gained by an electron or other simply charged particles when passing through a voltage difference of 1 Volt in vacuum. 1 eV is equal to the energy of 1.602 ยท 10-19 J. Derived greater units:

Kiloelectron volt (keV) = 1,000 eV
Megaelectron volt (MeV) = 1,000,000 eV
Gigaelectron volt (GeV) = 1,000,000,000 eV

Illustration of the electron volt energy unit