Coronium
Coronium was the name of an element postulated by John William Nicholson in 1911 (and previously by Mendeleev) based on spectral analyzes of galactic nebulae . According to this, coronium has an atomic weight of 0.51282.
The coronium is, however, the green emission line of the 13-fold positively charged Fe 13+ ion, [Fe XIV] at 530.3 nm. Since this is a forbidden line , the corresponding spectral line was very difficult to produce in earthly laboratories .
During the solar eclipse of August 7, 1869 , a green spectral line with a wavelength of 530.3 nm was independently observed by Charles Augustus Young and William Harkness in the solar corona . Since this spectral line did not seem to belong to any known element, it was assigned to an as yet unknown element, which was called coronium.
In 1903, Dmitri Ivanovich Mendeleev predicted two new chemical elements that were lighter than hydrogen and, by their nature, noble gases. Newtonium (element x) was his candidate for the all-pervading aether with an atomic mass of 0.17 and no charge. For coronium (element y) he predicted a maximum mass of 0.4 and considered it to be an inert gas homologous to neon . He saw evidence of coronium in the solar spectrum. It was not until the 1930s that Walter Grotrian and Bengt Edlén discovered that the 530.3 nm spectral line belongs to the highly ionized Fe 13+ .
Individual evidence
- ↑ Jan W. van Spronsen , Mendeleev as a speculator, Journal of Chemical Education, Volume 58, 1981, p. 790
- ^ Andrew Ede: The Chemical Element: A Historical Perspective . Greenwood Press, 2006, ISBN 0-313-33304-1 , pp. 83-84.