What physical quantity does electron volt (eV) measure? How is it related to the S.I. unit of that quantity?

Solutions:             

 Electron volt (eV) is used to measure the energy of atomic particles. It is given by –

1 eV = charge on an electron × 1 volt = 1.6 × 10^-19 coulomb × 1 volt

= 1.6 × 10^-19 J