rubidium definitions

WordNet (r) 3.0 (2005)

n
1: a soft silvery metallic element of the alkali metal group; burns in air and reacts violently in water; occurs in carnallite and lepidolite and pollucite [syn: rubidium, Rb, atomic number 37]

Merriam Webster's

noun Etymology: New Latin, from Latin rubidus red, from rub?re Date: 1861 a soft silvery metallic element of the alkali metal group that reacts violently with water and bursts into flame spontaneously in air — see element table

Dictionary of the Elements

rubidium
Symbol: Rb
Atomic number: 37
Atomic weight: 85.47
Soft silvery metallic element, belongs to group 1 of the periodic table. Rb-97, the naturally occurring isotope, is radioactive. It is highly reactive, with properties similar to other elements in group 1, like igniting spontaneously in air. Discovered spectroscopically in 1861 by W. Bunsen and G.R. Kirchoff.

Oxford Reference Dictionary

n. Chem. a soft silvery element occurring naturally in various minerals and as the radioactive isotope rubidium-87. Usage: Symb.: Rb. Etymology: L rubidus red (with ref. to its spectral lines)

Webster's 1913 Dictionary

Rubidium Ru*bid"i*um, n. [NL., fr. L. rubidus red, fr. rubere to be red. So called from two dark red spectroscopic lines by means of which it was discovered in the lepidolite from Rozena, Moravia. See Rubicund.] (Chem.) A rare metallic element. It occurs quite widely, but in small quantities, and always combined. It is isolated as a soft yellowish white metal, analogous to potassium in most of its properties. Symbol Rb. Atomic weight, 85.2.