Electronvolt

Electronvolt, a unit of energy used by physicists to express the energy of ions and subatomic particles that have been accelerated in particle accelerators. One electronvolt is equal to the amount of energy gained by an electron travelling through an electrical potential difference of 1 volt. One electronvolt is equivalent to 1.60207 × 10^-19 joules. The symbol for 1 electronvolt is eV. However, energies are commonly expressed as multiples of a thousand electronvolts (keV), of a million electronvolts (MeV), and of a billion electronvolts (GeV).