Question

If the bineding energy of the electron 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
A. `30.6eV`
B. `13.6eV`
C. `3.4eV`
D. `122.4eV`

Answer 1

Correct Answer - A
`E_(n) = (13.6)/(n^(2)) Z^(2) eV//atom`
for lithium ion` Z = 3 , n = 2 ` (for first excited state)
`E_(n) = (13.6)/(Z^(2)) xx 3^(2) = -30.6 eV`