Coronium
From Wikipedia, the free encyclopedia
Coronium was the name of a suggested chemical element, hypothesised in the 19th century. It was named after the solar corona.
In the 1860s, emission lines (particularly a green line) were observed in the coronal spectrum during solar eclipses that did not correspond to any known spectral lines. Again it was proposed that these were due to an unknown element, provisionally named coronium.
In 1902, in an attempt at a chemical conception of the Aether, Dimitri Mendeleev put forward a hypothesis that there existed two inert chemical elements of lesser atomic weight than hydrogen. Of these two proposed elements, he thought the lighter to be an all-penetrating, all-pervasive gas, and the slightly heavier one to be a proposed element, coronium.
It was not until the 1930s that it was discovered, by Walter Grotrian and Bengt Edlén, that the spectral lines were due to highly-ionised iron and nickel, the high ionisation being due to the extreme temperature of the solar corona.