Der Aufbau der Materie: Drei Aufsätze über moderne Atomistik und Electronentheorie La Constitution de la matière

Abstract

THE most important part of Prof. Max Born's work is contained in the second and third of his essays, where he shows that it is possible to obtain approximate values for the heat of chemical union of the halogen elements with the alkali metals and with hydrogen from purely physical data. In collaboration with Lande he has calculated the repulsive force between the Na + and Cl - ions in rock salt, which, combined with the ordinary Coulomb attractions and repulsions between these ions, accounts for the measured compressibility, and finds that this force may be written F = b/δⁿ, where b and n are constants and δ is the distance between neighbouring ions of the same kind. For sodium chloride and other halogen-alkali compounds n = 9. The law of force thus obtained is used to calculate the energy produced by the union of the ions to form the salt, which for one “Mol” is U = 545³ √rho;/(μ₊ + μ_–) kg. cal., where μ₊ is the atomic weight of the metal and μ_– that of the halogen. For absolute zero U_NaI = 158, U_KI = 144, when the ions are at rest in the position of equilibrium.

Der Aufbau der Materie: Drei Aufsätze über moderne Atomistik und Electronentheorie.

Von Max Born. Zweite, verbesserte Auflage. Pp. vi + 86. (Berlin: J. Springer, 1922.) 3s.

La Constitution de la matière.

Par Prof. Max Born. Traduit par H. Bellenot. (Collection de mono-graphies scientifiques étrangères, II.) Pp. iii + 84. (Paris: A. Blanchard, 1922.) 6 francs.