BOHR, N. (+) D. COSTER [DIRK].

Röntgenspektren und periodisches System der Elemente. Mit vier Abbildungen.

Berlin, Julius Springer, 1923. 8vo. Bound in contemporary half cloth with gilt lettering to spine. In "Zeitschrift für Physik", 12 band, 1923. The entire volume offered. Library stamp to title page. Internally a fine and clean copy. Pp. 272-286. [Entire volume: IV, 383 pp.].

First printing of Bohr's conceptions about atomic structure including electronic orbits. The paper was written in the months during which element 72 was discovered (first named Hafnia, the Latin name for Copehagen, then Danium, and finally the official name became Hafnium), and in the paper, element 72 is mentioned but not named. This is Bohr's first paper with joint authorship.

"Element 72 is included, but it is still indicated as unknown. In the second section of the paper a classification is given of the known X-ray spectra of 48 elements, from magnesium to uranium." (Bohr. Collected Works: The periodic system (1920-1923), p. 33).

The volume also contains the following paper by Erwin Schrödinger:
"Über eine bemerkenswerte Eigenschaft der Quantenbahnen eines einzelnen Elektrons" in which he made a new remarkable characteristic of the quanta channnel of a single electron.

Order-nr.: 49489