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 :

Step-by-step solution

Energy order of orbitals of H is decided by only principle quantum number (n) while energy order of H - is decided by ( n + l ) rule: Electronic configuration of ′ H - ′ is - 1 s 2 its energy order is decided by n + l rule. H - = 1 s 2 2 s 0 2 p 0 Its 2 n d   excited state is 2p And degeneracy 2 p   is   3 .