Rubidium

Rubidium
Properties
Atomic symbol	Rb
Atomic number	37
Classification	Alkali metal
Atomic mass	85.47 amu
Other Information
Date of discovery	1861
Name of discoverer	Bunsen, R.W. and Kirchoff, G.
Name origin	From the Latin Rubidius, meaning "deep red"
Uses	scientific research
Obtained from	lepidolite, pollucite, carnallite

Rubidium is an element in the alkali metals class of the periodic table. It is so chemically active that it is never found free (in elemental form) in nature, and can sometimes catch fire on mere exposure to air.

It was discovered by Robert Bunsen and Gustav Kirchoff, using their newly invented spectroscope. It (along with cesium) was identified by a previously unseen red spectral line in the analysis of mineral water from a German spa. The name comes from that color.