What's the difference between i.e. and e.g.?
unit of energy commonly used in atomic and nuclear physics, equal to the energy gained by an electron (a charged particle carrying unit electronic charge when the electrical potential at the electron increases by one volt). The electron volt equals 1.602 10-12 erg. The abbreviation MeV indicates 106 (1,000,000) electron volts and GeV, 109 (1,000,000,000).