rubidium.jpg (4714 bytes)
Rubidium examiner.


Symbol Name Atomic Number Atomic Weight Group Number
Rb Rubidium 37 85.4678 1


Standard State: solid at 298 K
Color: Silvery white

Rubidium was discovered in 1861 by Bunsen and Kirchoff in the mineral lepidolite by use of the spectroscope.  The element is much more abundant than was thought several years ago.  It is now considered to be the 16th most abundant element in the earth's crust.   Rubidium occurs in pollucite, carnallite, leucite, and zinnwaldite, which contains traces up to 1% in the form of oxide. It is soft silvery white metallic element of the  alkali group and is the second most electropositive and alkaline element.  It ignites spontaneously in air and reacts violently in water, setting fire to the liberated hydrogen. It colors a flame yellowish violet.  It must be kept under a dry mineral oil or in a vacuum or inert atmosphere.