On Electron Rings in the Atom

(J. Kroo. Der erste und zweite Elektronenring der Atome. Phys. ZS. 19, p. 307—1918).

As is known, according to Bohr atoms must be represented as consisting of a central positive nucleus, containing as many charges as the number of the element in the periodic system (the charge is considered equal and opposite in sign to the charge of the electron); around the nucleus, in orbits determined by experiments, move electrons, with each orbit being determined by the theory of quanta. Radiation is obtained if electrons from more distant orbits jump to orbits closer to the nucleus, and the number of oscillations of the emitted light is again determined by the quantum theory.

In application to X-ray spectra the Bohr model was first used by Moseley, who assumed that the atom has altogether two rings, with all the electrons initially situated on the outer ring, and then they successively jump to the inner ring, the one closest to the nucleus, and in doing so emit. Using such a representation, Moseley obtained for the \(K\)-series results approximately agreeing with experiment, supposing that the jumping of four electrons occurs simultaneously from the second ring (two-quantum) to the first (one-quantum). However, the structure of the \(K_{\alpha_1}\) series is more satisfactorily represented under the assumption that during emission only one electron jumps from a two-quantum orbit to a one-quantum orbit (Vegard). Debye showed that the assumption of the existence of 3 electrons in the normal state on the one-quantum ring leads to a formula for the \(K_{\alpha_1}\) series which also conveys the experimental data well, as does the formula obtained by Sommerfeld in investigations of the structure of X-ray spectra.

Kroo assumes that all Bohr orbits are supplied with electrons, and the \(K_{\alpha_1}\) series is obtained by the jumping of one electron from a two-quantum orbit to a one-quantum orbit.

According to Kroo, the \(K_{\alpha_2}\) series must be obtained when an electron moves along an ellipsoidal path, which is described by electrons obeying a definite law of arrangement in the orbit (for details see the original paper).

According to Kroo it follows that the one-quantum orbit must contain 3 electrons, the two-quantum orbit 8; under these assumptions, the values of the series calculated according to the theory and those obtained from experiment agree extremely well with one another.

P. Lazarev.