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 only principal quantum number (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 degeneracy 2p is '3'