Introduction to Atomic Physics

Abstract

The present and the following chapters aim at showing that the general theory expounded so far allows one to understand the general features of atomic energy levels. To this end, however, the attribution of an intrinsic angular momentum or spin to the electron will play an essential role: we have already mentioned that the theory, as it is at the present point of development, is not able to explain the existence of the anomalous Zeeman effect and we have also cited the discrepancies between theory and experiment that show up as a fine structure in the spectra of alkali atoms: these facts, and others that we will discuss, require the introduction of spin.