For principle quantum number `n = 4` the total number of orbitals having `l = 3`.

Options

A. 3
B. 7
C. 5
D. 9

Answer

B

Explanation

(b) `n = 4 rarr 1 s^2 2 s^2 2 p^6, 3 s^2 3p^6, 3 d^10, 4 s^2 4 p^6, 4 d^10 4 f^14`
So l = (n-1) = 4 -1 =3 is for f orbit which contains 7 orbitals.