protactinium

protactinium
A radioactive element, atomic no. 91, atomic wt. 231.03588, formed in the decay of uranium and thorium; its most long-lived isotope, 231Pa, has a half-life of 32,500 years. SYN: proactinium, protoactinium. [G. protos, first]

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prot·ac·tin·i·um .prōt-.ak-'tin-ē-əm also pro·to·ac·tin·i·um .prōt-ō- n a shiny metallic radioelement of relatively short life symbol Pa see ELEMENT (table)

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pro·tac·tin·i·um (Pa) (pro″tak-tinґe-əm) a radioactive metallic chemical element occurring along with radium in pitchblende, carnotite, and other minerals; atomic weight, 231; atomic number, 91.

Medical dictionary. 2011.

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  • PROTACTINIUM — Le protactinium (Pa) est l’élément chimique de numéro atomique 91. Tous ses isotopes sont radioactifs; deux d’entre eux existent dans la nature associés à la géochimie de l’uranium. L’isotope de masse 231, émetteur 見 de période 1/2 = 34 000 ans,… …   Encyclopédie Universelle

  • Protactinium — Thorium ← Protactinium → Uranium Pr …   Wikipédia en Français

  • Protactinium — The radioactive chemical element, of atomic number 91; Atomic symbol Pa; at. wt. of longest lived isotope, 231 (T1/2 = 32,500 yrs.) Also called brevium, Uranium X2 and UX2. [PJC] …   The Collaborative International Dictionary of English

  • protactinium — Symbol: Pa Atomic number: 91 Atomic weight: (231) Radioactive metallic element, belongs to the actinoids. The most stable isotope, Pa 231 has a half life of 2.43*10^4 years. At least 10 other radioactive isotopes are known. No practical… …   Elements of periodic system

  • protactinium — [prō΄tak tin′ē əm] n. [ModL: see PROTO & ACTINIUM] a rare, radioactive, metallic chemical element, one of the actinides, found in pitchblende: symbol, Pa; at. no., 91: see the periodic table of elements in the Reference Supplement …   English World dictionary

  • Protactinium — thorium ← protactinium → uranium Pr ↑ Pa ↓ …   Wikipedia

  • Protactinium — Eigenschaften …   Deutsch Wikipedia

  • protactinium — /proh tak tin ee euhm/, n. Chem. a radioactive, metallic element. Symbol: Pa; at. no.: 91. Also, protoactinium. [1915 20; PROT + ACTINIUM] * * * ▪ chemical element  (Pa),    radioactive chemical element of the actinoid series of the periodic… …   Universalium

  • Protactinium — Prot|ac|ti|ni|um auch: Pro|tac|ti|ni|um 〈n.; s; unz.; chem. 〉 radioaktives chem. Element, Ordnungszahl 91 [<grch. protos „erster, Ur...“ + Actinium] * * * Prot|ac|ti|ni|um [↑ proto u. ↑ Actinium (weil Letzteres aus P. entsteht)], das; s;… …   Universal-Lexikon

  • protactinium — protaktinis statusas T sritis chemija apibrėžtis Cheminis elementas. simbolis( iai) Pa atitikmenys: lot. protactinium angl. protactinium rus. протактиний …   Chemijos terminų aiškinamasis žodynas

  • protactinium — protaktinis statusas T sritis fizika atitikmenys: angl. protactinium vok. Protaktinium, n rus. протактиний, m pranc. protactinium, m …   Fizikos terminų žodynas

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