The energy of the emitted gamma ray is a precise measure of the difference in energy between the excited states of the decaying nucleus. In the case of conversion electrons, the binding energy must also be taken into account: The energy of a conversion electron is given as E = ( E i − − E f ) − − E B , where E i and E f are the energies of the nucleus in its initial and final states, respectively, while E B is the binding energy of the electron.