Correct set of four quantum numbers for the unpaired electron of chloride atom is — Atomic Structure Chemistry Question

💡 Solution & Explanation

A neutral chlorine atom (Z = 17) has the ground-state electronic configuration of [Ne] 3s^2 3p^5. The unpaired electron resides in the 3p subshell. Therefore, its principal quantum number is n = 3 and its azimuthal quantum number is l = 1. Evaluating the options: (a) l=2 (incorrect), (c) s=0 (incorrect), (d) l=0 (incorrect). Set (b) correctly gives n=3, l=1 with m=0 and s=+1/2, which are permissible and correct.