Reading the Spectrum, Ch Atoms in a magnetic field: moments, the Zeeman effect and the Paschen-Back limit
Problem
Suppose someone tries to rescue the spinless picture: "Sodium's 589.6nm line splits into four components only because the orbital moment is bigger than we assumed. Replace μz=−mlμB by μz=−gmlμB with some g=1, the same for every level, and the pattern will follow."
((a)) In this model, find the possible line shifts allowed by Δml=0,±1, and say how many components any line would show.
((b)) The lower level of this line is sodium's ground level, with l=0. What does this model predict for that level in a field, and what does a Stern-Gerlach beam of ground-state atoms with l=0 show instead?
((c)) Name the two properties a second moment must have to account for these facts, and give the evidence for each.