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

Because a vanadium peroxide molecule is negatively charged, it needed alkali cations for charge balance, Nyman said, and the researchers used potassium, rubidium and cesium alkali cations for this study.

From Science Daily

An effort spanning the last several years, the Harvard platform is built on an array of very cold, laser-trapped rubidium atoms.

From Science Daily

Next they illuminated that atom with another laser tuned to rubidium’s scattering preference and placed a lens off to the side to collect the scattered light and channel it into an optical fiber.

From Scientific American

A new economic assessment will also be carried out to include byproducts potassium, cesium and rubidium, which were not analyzed in the original study, Clarke said.

From Reuters

One table is responsible for producing laser light for trapping, cooling and imaging rubidium atoms.

From Scientific American