(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

For a many electron system with L=2,S=1 and J=2 calculate the angle between the L and S vectors both according to the old quantum theory and quantum mechanics.

2. Relevant equations

3. The attempt at a solution

I suppose this problem is nothing but a simple application of cosine rule.The external angle is the answer.

But I am thinking twice as they mention: both according to the old quantum theory and quantum mechanics.

Am I missing something?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Spectroscopy question

**Physics Forums | Science Articles, Homework Help, Discussion**