Stern-gerlach vs zeeman effect = paradox?

[Aziza]

This may be a stupid question, but I am reviewing for the physics gre and can't help but see the zeeman effect and stern-gerlach experiments as contradictions. In the Zeeman effect, a neutral atom energy level will split into 3 levels (or 2 or more if take into account anomalous zeeman), but in stern-gerlach, it always only splits in two (the beam deflected upwards has higher energy than the beam deflected downwards).

Could someone please help me resolve this contradiction?


Thanks!

 

[Jilang]

In the Zeeman effect what comes into play is the difference in the energy levels between the electrons in the atom.
http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/zeeman.html
However in the Stern Gerlach experiment what is important is the angular momentum of the atoms as a whole.