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rubidium
[ roo-bid-ee-uhm ]
noun
, Chemistry.
- a silver-white, metallic, active element resembling potassium, used in photoelectric cells and radio vacuum tubes. : Rb; : 85.47; : 37; : 1.53 at 20°C.
rubidium
/ ruːˈbɪdɪəm /
noun
- 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 × 10 11years; valency: 1, 2, 3, or 4; relative density: 1.532 (solid), 1.475 (liquid); melting pt: 39.48°C; boiling pt: 688°C
rubidium
/ ro̅o̅-bĭd′ē-əm /
- A soft, silvery-white metallic element of the alkali group. It ignites spontaneously in air and reacts violently with water. Rubidium is used in photoelectric cells, in making vacuum tubes, and in radiometric dating. Atomic number 37; atomic weight 85.47; melting point 38.89°C; boiling point 688°C; specific gravity (solid) 1.532; valence 1, 2, 3, 4.
- See Periodic Table
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Derived Forms
- ruˈbidic, adjective
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Other Words From
- ru·bidic adjective
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Word History and Origins
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Word History and Origins
Origin of rubidium1
C19: from New Latin, from Latin rubidus dark red, with reference to the two red lines in its spectrum
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Example Sentences
He picked up a shard of rubidium that served as a paper weight and toyed with it.
From Project Gutenberg
In rubidium the lines Rb and Rb in the blue, and Rb in the red are almost equally specific.
From Project Gutenberg
The separation of lithium, cæsium, and rubidium is seldom called for, owing to their rarity.
From Project Gutenberg
Cæsium and rubidium are separated from potassium by fractional precipitation with platinum chloride.
From Project Gutenberg
Rubidium occurs widely diffused in nature, but in very small quantities.
From Project Gutenberg
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