1. The problem statement, all variables and given/known data The PE of a magnetic moment in an external magnetic field is given by U = -u dot B. Calculate the difference in energy between the two possible orientations of an electron in a magnetic field B = .6k T 2. Relevant equations 3. The attempt at a solution I realize electrons can have an up spin and down spin, but I am having a hard time doing this problem. I believe I should be using g = 2 for the gyromagnetic ratio. So: (_h = h bar) uz = -g uB JZ/_h uB = e(_h)/(2me) Unfortunately then I don't know what I should have for Jz. (This is defined by my book as "any type of angular momentum). So I guess my problem is that I don't know what I should use for angular momentum, since n and l aren't defined in the problem. Can anyone help clear this up?