Question: what is the difference between 1 volt and 1 electron volt?
Answer: One eV is equal to the amount of energy one electron acquires by accelerating (from rest) through a potential difference of one volt. It is usually used as a measure of particle energies although it is not an SI (System International) unit. The SI unit for energy is the JOULE. 1 eV = 1.602 x 10-19 joule.