An electron volt (also written electron-volt and eV) is a unit of energy, specifically the energy that it takes to move an electron through the potential difference of 1 volt (or a proton moving through the same potential difference, in a different direction).[1] This small unit of energy is useful when discussing the energy released from chemical reactions or moving electrons closer or further from the nucleus in an atom.

When converting from mass to energy the MeV (mega electron volt) is useful. This leads to a derived unit of mass the MeV/c2, which is useful for looking at nuclear reactions.


For Further Reading


  1. Jean Tate. (February 17, 2010). The Electronvolt [Online]. Available: [February 20, 2015].