Electrostatics: Electric Potential

Electron Volt

Since the Joule is such a large unit when comparing it to the energies involved in moving electrons, atoms, or molecules, scientists use the unit electron Volt (eV). It is defined as the energy acquired by a particle carrying a charge equal to an electron by moving through a potential difference of 1 V.

1 electron Volt equals q times V equals 1 point 6 times ten to the negative nineteenth Coulombs times one point zero volts equals one point six times ten to the negative nineteenth Joules.

Though it is a good way to refer to the energies involved in moving charges, it is not an SI unit. It is a derived unit. If a problem refers to an electron Volt, it should be converted to Joules before doing any calculations for energy.