a soft, silvery-white, metallic chemical element, one of the alkali metals, that ignites spontaneously in air and reacts violently in water: used in photocells and in filaments of vacuum tubes: symbol, Rb; at. no. 37
Origin of rubidiumModL: so named (1861) by R. W. Bunsen and amp; G. R. Kirchhoff ; from Classical Latin rubidus, red ; from ruber, red (from the red lines in its spectrum) + -ium
A soft silvery-white metallic element of the alkali group that ignites spontaneously in air and reacts violently with water, used in photocells and as a getter in the manufacture of vacuum tubes. Atomic number 37; atomic weight 85.47; melting point 39.30°C; boiling point 688°C; specific gravity (solid) 1.532; valence 1, 2, 3, 4. See Periodic Table.
Origin of rubidiumFrom Latin r&umacron;bidus, red; see reudh- in Indo-European roots.