If ℓ=0, then j=s, mj=ms, and the "good" states are the same (∣nms⟩) for weak and strong fields. Determine EZ1 (from Equation 7.74) and the fine structure energies (Equation 7.69), and write down the general result for the ℓ=0 Zeeman effect—regardless of the strength of the field. Show that the strong-field formula (Equation 7.86) reproduces this result, provided that we interpret the indeterminate term in square brackets as 1.