Q25 · CSIR-NET Chemistry, June 2015

Paper: CSIR-NET June 2015 · Subject: Physical Chemistry · Chapter: Atomic and Molecular Term Symbol · Topic: Selection Rules · Marks: 2 · Difficulty: Easy

The electric-dipole allowed transition among the following is

(a)${ }^{3} \mathrm{S} \rightarrow{ }^{3} \mathrm{D}$

(b)${ }^{3} \mathrm{S} \rightarrow{ }^{3} \mathrm{P}$

(c)${ }^{3} \mathrm{S} \rightarrow{ }^{1} \mathrm{D}$

(d)${ }^{3} \mathrm{S} \rightarrow{ }^{1} \mathrm{F}$

Answer

Answer: B ✓ checked by 4AB · confidence high

Explanation

Electric-dipole selection rules: ΔS = 0 and ΔL = ±1. Only ³S → ³P satisfies both; ³S → ³D has ΔL = 2 and the singlet targets break ΔS = 0.

Study loop for Atomic and Molecular Term Symbol