radium

American  

[rey-dee-uhm] / ˈreɪ di əm /

noun

1. Chemistry. a highly radioactive metallic element whose decay yields radon gas and alpha rays. Ra; 226; 88.

2. a lustrous rayon or silk fabric constructed in plain weave and used in women's apparel, lining, and drapery.

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radium British  

/ ˈreɪdɪəm /

noun

1. 1. a highly radioactive luminescent white element of the alkaline earth group of metals. It occurs in pitchblende, carnotite, and other uranium ores, and is used in radiotherapy and in luminous paints. Symbol: Ra; atomic no: 88; half-life of most stable isotope, ²²⁶ Ra: 1620 years; valency: 2; relative density: 5; melting pt: 700°C; boiling pt: 1140°C

   2. ( as modifier )

      radium needle

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radium Scientific  

/ rā′dē-əm /

1. A rare, bright-white, highly radioactive element of the alkaline-earth group. It occurs naturally in very small amounts in ores and minerals containing uranium, and it is naturally luminescent. Radium is used as a source of radon gas for the treatment of disease and as a neutron source for scientific research. Its most stable isotope is Ra 226 with a half-life of 1,622 years. Atomic number 88; melting point 700°C; boiling point 1,737°C; valence 2.

2. See Periodic Table

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radium Cultural  

1. A naturally occurring radioactive chemical element. Its symbol is Ra.

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Discover More

Radium was discovered by the chemists Marie and Pierre Curie.

Etymology

Origin of radium

1895–1900; < New Latin, equivalent to Latin rad ( ius ) ray ( radius ) + -ium -ium

Example Sentences

But then, he predicted that industries would start using uranium and radium, and pretty soon we’d have … radioactive smog.

From Los Angeles Times

This surprising finding led to the discovery of polonium and radium and helped establish the field of nuclear physics and chemistry.

From Science Daily

Part of that included disposing of glowing dials, which were made using radium-226.

From BBC

By using the molecular environment as a microscopic stand-in for a particle collider, they confined the radium atom's electrons and increased the likelihood that some would briefly pass through the nucleus.

From Science Daily

It contains radium that decays into radon gas, which is radioactive and can cause cancer.

From Barron's