rubidium

[ roo-bid-ee-uhm ]

noun

, Chemistry.

1. 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

1. 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 /

1. 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.
2. See Periodic Table

Derived Forms

• ruˈbidic, adjective

Other Words From

• ru·bidic adjective

Word History and Origins

Origin of rubidium¹

1860–65; < New Latin, equivalent to Latin rūbid ( us ) red (in allusion to the two red lines in its spectrum) + -ium -ium

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

Example Sentences

So Scarani and colleagues studied entangled rubidium atoms 400 meters apart.

From Science News

Holynski’s team solved that problem by building a gravity sensor with not one but two falling clouds of rubidium atoms.

From Science News

Kasevich and colleagues launched rubidium atoms inside a 10-meter-tall vacuum chamber, hit them with lasers to put them in quantum superpositions tracing two different paths, and watched how the atoms fell.

From Science News

They then prepared rubidium atoms with spins aligned in a particular direction, and sent the atoms drifting toward the barrier.

From Quanta Magazine

In the Cold Atom Lab, rubidium atoms reached tenths of billionths of kelvins.

From Science News

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