The Spectra of Tin and Their Zeeman Effects

Analysis of the spectra of Sn, Sn I, Sn II, Sn III.—(1) Zeeman effects of the lines of the tin spectrum have enabled the authors to classify the spectra of tin in the neutral state and in two stages of ionization. (2) The spectrum of neutral tin has 5 low levels, ${}_{}{}^3{}_{}{}^{}P_{012}^{}{}_{}{}^{}$, ${{}_{}{}^1{}_{}{}^{}D_2^{}{}_{}{}^{}}^{\prime }$, ${{}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{}}^{\prime }$, due to the configuration $5_2$ $5_2$. The configuration $5_2$ $6_1$ yields ${{}_{}{}^3{}_{}{}^{}P_{012}^{}{}_{}{}^{}}^{\prime }$ and ${{}_{}{}^1{}_{}{}^{}P_1^{}{}_{}{}^{}}^{\prime }$. The configuration $5_2$ $5_3$ yields twelve terms of which the four lowest are definitely established. Pauli's $g$-sum rule is found to be valid. The ionization potential of SnI is calculated as 7.37±.05 volts and the resonance potential 4.30 volts. (3) The spectrum of Sn II is a doublet spectrum like In I and the principal doublet separation found from some results of Lang is found to be 4253 ${\mathrm{cm}}^{-1\mathrm{}}$. Several series are noted, including lines due to abnormal states, the electrons having the configuration $5_1$ $5_2$ $5_2$. The ionization potential is computed as approximately 14.5 volts and the resonance potential 6.5 volts. (4) The spectrum of Sn III consists of singlets and triplets, like that of Cd I. Several series are noted, and the ionization potential calculated as about 30 volts, and the resonance potential as 6.81 volts. A very strong group in the extreme ultra-violet is classified as a $p{p}^{\prime }$ group. (5) Application of the regular doublet law leads to possible classifications in the spectra of In II, and Ge II.