Definition of rubidium
: 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
Recent Examples of rubidium from the Web
Image: Individual rubidium atoms form into a single super-atom in a Bose-Einstein condensate.
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Origin and Etymology of rubidium
New Latin, from Latin rubidus red, from rubēre
First Known Use: 1861See Words from the same year
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