in the zeeman effect, there are degeneracy levels due to the the magnetic quantum number which when placed in a magnetic field, the degeneracy is broken. is there a way to see the degeneracy of the angular momentum? since Energy is only effected by the principal quantum number, there should be a degeneracy for electrons in the n=2 shell, which can have angular momentum l=0 and l=1 right? is there an effect (like the zeeman effect) that breaks this energy degeneracy? also, what quantum number does the start effect break in degeneracy? is it also the magnetic quantum number?