Selection rules for spectral transitions of atoms where Russell-Saunders coupling is valid are (Bethe and Jackiw, Chapter 11) ˆ†L = 0, ± 1; ˆ†S = 0; ˆ†J = 0, ± 1 (but J = 0 to J = 0 is forbidden); ˆ†(Σili) = (1, meaning that the change in configuration must change the sum of the l values of the electrons by ±1. For most atomic spectral lines, only one electron changes its subshell; here the ˆ†(Σili) = ± 1 rule becomes ˆ†l = ±1 for the electron making the transition.
For the carbon atom, the levels that arise from the 1s22s22p2 configuration are

And the energy levels of the 1s22s2p= configuration are

Use the above selection rules to find the wavenumbers of all the transitions that are allowed between pairs of these 15 levels.

Transcribed Image Text:

Level 3Po 3 P D2 (E/hc)/cm6.4 434 10192.6 21648.0 D2 33735.2 64086.964089.8 64090.9 75254.0 75255.3 752561 D2 97878 105798.7 119878