Explanation:
Formula for energy value is as follows.
           E = [tex]\frac{-E_{0}}{n^{2}}[/tex]
where, Â Â Â [tex]E_{0}[/tex] = 13.6
             n = number of shell             Â
So, at ground state energy  of hydrogen atom will be as follows.
          E = [tex]\frac{-E_{0}}{n^{2}}[/tex]
            = [tex]\frac{-13.6}{(1)^{2}}[/tex]
           = -13.6
Hence, for an ionized atom value of energy will be as follows.
          E' = [tex]-13.6 \times Z^{2}[/tex]
  or,       E' = [tex]E \times Z^{2}[/tex]
Thus, we can conclude that total energy of the remaining electron in the ionized atom is [tex]E \times Z^{2}[/tex].
