ALL meanings of rubidium
ru·bid·i·um
R r - noun rubidium a silver-white, metallic, active element resembling potassium, used in photoelectric cells and radio vacuum tubes. Symbol: Rb; atomic weight: 85.47; atomic number: 37; specific gravity: 1.53 at 20°C. 1
- noun rubidium chemical element 1
- noun rubidium a soft highly reactive radioactive element of the alkali metal group; the 16th most abundant element in the earth's crust (310 parts per million), occurring principally in pollucite, carnallite, and lepidolite. It is used in electronic valves, photocells, and special glass. Symbol: Rb; atomic no: 37; atomic wt: 85.4678; half-life of 87Rb: 5 × 1011 years; valency: 1, 2, 3, or 4; relative density: 1.532 (solid), 1.475 (liquid); melting pt: 39.48°C; boiling pt: 688°C 0
- noun rubidium 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 0