The normal Zeeman effect: three lines, the Lorentz unit, and the polarization of the \(\pi\) and \(\sigma\) components.

The anomalous Zeeman effect and the Landé \(g\) factor.

Counting Zeeman components for any transition.

The Paschen–Back effect, and why a strong field restores the simple triplet.

The Stark effect: the linear effect in the degenerate \(n=2\) level of hydrogen, and the quadratic effect elsewhere.