23 September 2009
Rubidium, element 37, was discovered by two Germans, chemist Robert Bunsen (of burner fame) and physicist Gustav Kirchhoff, using a spectroscope. The element was identified by two distinctive lines in the red portion of the spectrum. Hence the name, which is from the Latin rubidus, or red.
The name first appears in German in 1861 in Annalen der Physik und Chemie, followed shortly by its appearance in English in the Proceedings of the Royal Institutution that same year:
A few days ago the speaker received a letter from Bunsen, which contains the following most interesting information:—"The substance which I sent you as impure tartrate of Cæsium contains a second new alkaline metal [...] I propose to call the new metal ‘Rubidium.’”
Rubidium has the chemical symbol Rb.
Sources:
Oxford English Dictionary, rubidium, 2nd Edition, 1989