If the binding energy of the electron in a hydrogen atom is `13.6 eV`, the energy required to remove the electron from the first excited state of `Li^(++)` is

Options

A. `30.6 eV`
B. `13.6 eV`
C. `3.4 eV`
D. `122.4 eV`

Answer

A

Explanation

Energy required to remove an electron from an orbit is `+ (13.6(Z)^(2))/n^(2) eV`
So, to remove the electron from the first excited state of `Li^(2+)` is
`E=(+13.6xx3^(2))/2^(2)=3.4xx9= +30.6 eV`