electron-volt

n. a unit of energy, being equal to the kinetic energy acquired by an electron when accelerated through a potential difference of one volt. It is equal to 1.602 x 10-19 Joules. It is abbreviated eV. The unit electron-volt is often used to express the rest mass and the energy of fundamental particles, especially when accelerated to high velocity in an accelerator. In accelerators, the units encountered are more commonly megaelectron-volts (MeV or million electron-volts) and giga-electron-volts (GeV or billion electron-volts). [ PJC ]