radium

[ rey-dee-uhm ]

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.

radium

/ 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, ²²⁶Ra: 1620 years; valency: 2; relative density: 5; melting pt: 700°C; boiling pt: 1140°C
   2. ( as modifier )

      radium needle

radium

/ 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

radium

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

Notes

Radium was discovered by the chemists Marie and Pierre Curie .

Word History and Origins

Origin of radium¹

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

Word History and Origins

Origin of radium¹

C20: from Latin radius ray

Example Sentences

It was full of heavy metals and radium, a by-product of uranium’s decay.

From Popular-Science

Where there’s now a hump of radium and dust, the community envisions an event center that could host car shows and concerts.

From Popular-Science

The heap contains radium, which uranium produces when it decays.

From Popular-Science

We know now that radium, or at least radio-active substances, represent the philosopher's stone of the olden time.

From Project Gutenberg

Radium was discovered in 1898 by M. and Madame Curie and M. Bmont, while experimenting with the uranium mineral pitchblende.

From Project Gutenberg

It seems that an atom of radium does actually disintegrate, and by disintegrating give out energy.

From Project Gutenberg

"They are using radium repellent rays to keep us from approaching," he informed.

From Project Gutenberg

The cost of one pound of radium is variously estimated at from one to three millions of dollars.

From Project Gutenberg