Basically, what is the Zeeman Effect and how is it caused. This isn't really a homework question, just trying to clear up my understanding and for my own notes. Ok well, this is what my current understanding is: The normal Zeeman Effect to be the splitting of spectral lines when a magnetic field is applied. It is caused by the interaction between the magnetic field and the varying angular momentum of the electrons. Under normal conditions in the absence of a magnetic field, the quantum states are degenerate and hence only one spectral line appears. However, how come a Hydrogen atom exhibits the normal Zeeman Effect? It only has one electron and hence one angular momentum quantum number assigned to it, so wouldn't it not demonstrate it? I'd understand why a p-orbital with 3 different angular momentum quantum number separates into 3 spectral lines when placed in a magnetic field but not Hydrogen. Also can someone please explain the anomalous Zeeman Effect? I know it to be the normal Zeeman Effect but with the effects of the electron spin being considered but don't really know anything else. I'm looking at http://hyperphysics.phy-astr.gsu.edu/Hbase/quantum/zeeman.html" [Broken] and the diagrams in the anomalous Zeeman Effect section is completely throwing me off.