The Variation of theKResonating Strength with Atomic Number

Abstract

The resonating strength of the $K$-shell or the effective number $N_K$ of $K$ electrons is less than 2 and varies with atomic number. It is determined in the present paper by an approximate theory using Hartree wave functions. The results are compared with $N_k$ values obtained by anomalous dispersion, by computation from the most reliable absorption experiments, and by an approximate absorption theory of Hönl and Williams. Below atomic number 40 the present theory gives good results and allows of the determination of the $N_k$ values which are needed in finding absolute x-ray wave-lengths from dispersion measurements.