LV.The electronic energy levels of the elements, with special reference to their connexion with the sizes and electronic states of atoms in metallic crystals

Abstract

1. If Z is the Atomic Number the interatomic distances in the crystals of the elements vary as for the elements at the beginning of the first, second, third, and fourth Periods respectively. At the same time the electronic energy levels vary linearly with Z², Z⁴, Z⁶, and Z⁰ for the N₁ electrons of the outermost group of electrons of the atomic core or ion (i. e. the 2₁ electrons for Sodium, Magnesium, etc., the 3₁ electrons for Potassium, Calcium, etc.), and this linear relation is often a direct proportionality. 2. This empirical correspondence, whereby a variation of the interatomic distance as accompanies a variation of the electronic energy level terms as Z^2x , has been used for a detailed discussion of the interatomic distances in the crystals of the transitional elements of the Long Periods, and a method is suggested for determining the electronic states of the atoms in the solid crystals, as distinct from those in the free vapour. The main con-conclusion is that in the solid crystals the transition process only begins at Group VI., whereas in the case of free atoms it begins at Group III. 3. For the valency electrons it is shown that in Groups O, I. A, and II. A, if V is the ionization potential, a linear relation exists between n ²V and Z ^2/3 for the members of any one group where n is the quantum number of the electron. 4. Recent data show that in Group O (the Rare Gases) the interatomic distances (d), agree with the Law of the Sub-Groups, , where n is the principal quantum number of the outermost shell of electrons of the atomic core, which in this group is the outermost shell in the atom. The value of x is very nearly as in Groups I. A, II. A, and IV. A.