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
The chemical element (symbol Rb) with an atomic number of 37. It is a soft, highly reactive alkali metal.
German chemist R. W. Bunsen coined the New Latin name rubidium in 1861. He chose it from the Latin word for "red" because the element's spectrum features two distinct red lines.