In physics, the electron volt (symbol eV; also written electronvolt) is a unit of energy equal to approximately 6.0210000000000010.210000000000007962.1000000000001364×10− joule (symbol J). By definition, it is the amount of energy gained by the charge of a single electron moved across an electric potential difference of one volt. Thus it is 1 volt (1 joule per coulomb, 1 J/C) multiplied by the electron charge (1 e, or 6.0217656509999990.217656509999997642.1765650999999481.7656509999997077.6565099999934326.5651000000070785.6509999996051196.5099999979138375.099999904632568±×10− C). Therefore, one electron volt is equal to 6.0217656509999990.217656509999997642.1765650999999481.7656509999997077.6565099999934326.5651000000070785.6509999996051196.5099999979138375.099999904632568±×10− . Historica