Not considering the electronic spin, the degeneracy of the second excited state `(n = 3)` of H-atom is 9, while the degeneracy of the second excited state of `H^(-)` is

Answer

3

Explanation

Energy order of orbitals of `H` is decided by principle quantum umber (n)
while energy order of `H^(-)` is decided by `(n+l)` rule:
Electronic configuration of `'H^(-)'` is `-1s^(2)` its Energy order is decided by `n+l` rule.
`H^(-)=1s^(2)2s^(0)2p^(0)`
Its `2^(nd)` excited state is `2p`
and degenery `2p` is `'3'`