Question

Not considering the electron spin, the degeneracy of second excited state is 9, while the generality of the first excited state of $H$ atom is:

• A. 1
• B. 2
• C. 3
• D. 4

Answer 1

The correct option is A 1

Single electron species don't follow the $H$ rule and all orbitals of a particular shell have same energy and are called degenerate orbitals$.$

Therefore$,$ second excited state of $H(n=3)$ will have $9$ orbitals of same energy $i.e;$ degeneracy$=9$

Ground state of $H^{-}=1s^2$

First excited state of $H^{-}=1s^1,2s^1$

Hence. option $\left(A\right)$ is correct answer.