The K Emission Spectra for Elements Tin (50) to Hafnium (72)

Using an x-ray tube and transmission spectrograph as previously described, measurements were made of the K series emission wave-lengths of elements from Sn (50) to Hf (72), except Xe (54) and Ho (67). The $\beta$ line is resolved for most of the elements into two components ${\beta }^{\prime }$ and $\beta$, having a wave-length difference of about.76 x-units. The wave-length difference between the ${\alpha }^{\prime }$ and $\alpha$ lines varies from about 4.4 x-units for tin to 4.84 x-units for hafnium. This doublet difference when plotted with atomic number gives a curve with slight irregularities for groups of points, which may bear a relation to the method of adding additional electrons in the process of atom building.