What is the Difference Between Normal and Anomalous Zeeman Effect?

The Zeeman effect refers to the splitting of spectral lines of an atomic spectrum in the presence of a magnetic field. There are two types of Zeeman effects: normal and anomalous. The main differences between these two effects are:

1. Origin: The normal Zeeman effect occurs when the spectral lines result from a transition between singlet states, while the anomalous Zeeman effect occurs when the total spin of either the initial or final states, or both, is nonzero.
2. Spectral Line Splitting: The normal Zeeman effect results in the formation of triplets by splitting a single spectral line into three equally spaced components. In contrast, the anomalous Zeeman effect results in the formation of four or more spectral line splittings due to the nonzero spin angular momentum.
3. Magnetic Moment: The normal Zeeman effect is due to only orbital angular momentum, while the anomalous Zeeman effect is due to nonzero spin angular momentum, which creates additional spectral line splitting.
4. Energy-Level Splitting: In the normal Zeeman effect, the energy-level splitting is simpler, as it depends only on the orbital angular momentum. In the anomalous Zeeman effect, the energy-level splitting is more complicated because the total magnetic moment is not parallel to the total angular momentum.

In summary, the main difference between the normal and anomalous Zeeman effects lies in the origin of the spectral line splitting, with the normal effect being due to orbital angular momentum and the anomalous effect being due to nonzero spin angular momentum. This leads to different numbers of spectral line splittings and more complex energy-level splittings in the anomalous case.

Comparative Table: Normal vs Anomalous Zeeman Effect

The main difference between normal and anomalous Zeeman effects lies in the splitting of spectral lines in the presence of an external magnetic field. Here is a table comparing the two effects:

In summary, the normal Zeeman effect is a simpler phenomenon where the spectral lines split into three equally spaced components due to the interaction between the external magnetic field and the orbital angular momentum of the atom. In contrast, the anomalous Zeeman effect involves more complex splitting patterns due to the contribution of both orbital angular momentum and nonzero spin angular momentum.