- 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.
Origin of rubidium
1860–65; < New Latin, equivalent to Latin rūbid(us) red (in allusion to the two red lines in its spectrum) + -ium -ium
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Examples from the Web for rubidium
He picked up a shard of rubidium that served as a paper weight and toyed with it.The Stutterer
Lithia and fluorine are each present to the extent of about 5%; rubidium and caesium are sometimes present in small amounts.
At Pala it has been extensively mined for the preparation of lithium and rubidium salts.
In rubidium the lines Rb and Rb in the blue, and Rb in the red are almost equally specific.
The separation of lithium, cæsium, and rubidium is seldom called for, owing to their rarity.A Textbook of Assaying: For the Use of Those Connected with Mines.
Cornelius Beringer and John Jacob Beringer
- 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 87 Rb: 5 × 10 11 years; valency: 1, 2, 3, or 4; relative density: 1.532 (solid), 1.475 (liquid); melting pt: 39.48°C; boiling pt: 688°C
C19: from New Latin, from Latin rubidus dark red, with reference to the two red lines in its spectrum
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
- A soft metallic element of the alkali group. Atomic number 37.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- 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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