Which of the following statements related to fine structure of sodium D-Line…

PYQ UPPSC LT Grade (Assistant Teacher) 2025

1. A.

   Fine structure is obtained due to transition from energy levels 3p to 3s.

2. B.

   Sodium D-line belongs to principal series.

3. C.

   Selection rules for transition are ΔL = ± 1 and ΔJ = 0, ± 1.

4. D.

   Due to spin orbit interaction, both 3p and 3s energy states split into two energy states.