radium emanation
Radon Ra"don (r[=a]"d[o^]n), n. (Chem.) An intensely radioactive gaseous element produced by the radioactive decay of radium-226, which is the main isotope of radium found in pitchblende. Chemically it is an inert noble gas. Its atomic symbol is Rn. It has an atomic number of 86. The radon isotope produced by decay of radium has an atomic weight of 222.017, and this isotope decays by alpha emission with a half-life of 3.82 days. Numerous other isotopes have been observed, all radioactive and all having half-lives shorter than that of radon-222. Radon was discovered by M. and Mme. Curie, of Paris, in their studies of the radioactive substances in pitchblende. Radon was originally called {radium emanation} or {exradio}. [PJC]

The Collaborative International Dictionary of English. 2000.

Look at other dictionaries:

  • radium emanation — n RADON …   Medical dictionary

  • Radium-Emanation — Ra|di|um E|ma|na|ti|on [↑ Emanation] svw. ↑ Radon …   Universal-Lexikon

  • radium emanation — Chem. (formerly) radon. [1900 05] * * * …   Universalium

  • radium emanation — radon (Chemistry) …   English contemporary dictionary

  • radium emanation — /reɪdiəm ɛməˈneɪʃən/ (say raydeeuhm emuh nayshuhn) noun → radon …   Australian English dictionary

  • radium emanation — noun : radon 1 …   Useful english dictionary

  • émanation — [ emanasjɔ̃ ] n. f. • 1579; lat. ecclés. emanatio ♦ Action d émaner; la chose qui émane. 1 ♦ Théol. Manière dont le Fils procède du Père, et le Saint Esprit du Père et du Fils. ⇒ procession. ♢ Philos. Processus par lequel les êtres et le monde… …   Encyclopédie Universelle

  • Emanation (Physik) — Emanation ist ein Oberbegriff für die Freisetzung von Material in nicht fester oder flüssiger Form aus zumeist festen Ausgangsverbindungen. Der Ausdruck wird benutzt in der Mineralogie, Geologie, Physik und Chemie. Ein Beispiel der Emanation ist… …   Deutsch Wikipedia

  • Radium — (pronEng|ˈreɪdiəm) is a radioactive chemical element which has the symbol Ra and atomic number 88. Its appearance is almost pure white, but it readily oxidizes on exposure to air, turning black. Radium is an alkaline earth metal that is found in… …   Wikipedia

  • Radium — Ra di*um (r[=a] d[i^]*[u^]m), n. [NL., fr. L. radius ray.] (Chem.) An intensely radioactive metallic element found (combined) in minute quantities in pitchblende, and various other uranium minerals. Symbol, Ra; atomic weight, 226.4. Radium was… …   The Collaborative International Dictionary of English

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