Electron volt and its significance

Electron volt is the energy acquired by an electron to accelerated through a potential difference of one volt

Magnitude of electron charge e=1.6*10^-19, accelerating potential difference V=1volt
Then the energy acquired by an electron when accelerated through 1 volt P.D. is
W=qV
=1.6*10^-19*1J and is called one electron volt(eV)
To convert the joule to electron volt, one has to divide the value in joul by charge of electron.
The energy levels and ionization energies of atoms and binding energies of molecules are usually expressed in electron volts.
The eV is too small a unit for expressing energies in nuclear physics.