The hydrogen -like species `Li^(2+)` is in a spherically symmetric state `S_(1)` with one node. Upon absorbing light , the ion undergoes transition to a state `S_(2)`. The state `S_(2)` has one radial node and its energy is equal is to the ground state energy of the hydrogen atom.
Energy of the state `S_(1)` in units of the hydrogen atom ground state energy is

Options

A. `4.50`
B. `1.50`
C. `2.25`
D. `0.75`

Answer

C

Explanation

Energy of state `S_1 =-13.6(3^2/2^2)` eV/atom =`9/4` (energy of H-atom in ground state)
2.25 (energy of H-atom in ground state )