1. The problem statement, all variables and given/known data What is the significance of quantization of angular momentum in the absence of magnetic field? 2. Relevant equations Lz=mlh/2∏;Jz=mjh/2∏;Sz=msh/2∏. 3. The attempt at a solution I read that in the absence of magnetic field,z-axis direction is arbitrary and the component of L along whatever direction we choose must be mlh/2∏.How can this be true?Moreover I think, say in 2p state,each of the 3 ml values(-1,0,1)are assigned to uniquely to each of 2px,2py and 2pz.This is also not in accordance with space quantization concept. Please anyone explain this to me.