Symbol: Pm
Atomic number: 61
Atomic weight: (147)
Soft silvery metallic element, belongs to the lanthanoids. Pm-147, the only natural isotope, is radioactive and has a half-life of 252 years. Eighteen radioisotopes have been produced, but all have very short half-lives. Found only in nuclear decay waste. Pm-147 is of interest as a beta-decay source, however Pm-146 and Pm-148 have to be removed from it first, as they generate gamma radiation. Discovered by J.A. Marinsky, L.E. Glendenin and C.D. Coryell in 1947.

Elements of periodic system. 2013.

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  • Promethium — (pronEng|prəˈmiːθiəm/, /proʊˈmiːθiəm) is a chemical element with the symbol Pm and atomic number 61. It is notable for being the only other exclusively radioactive element besides technetium which is followed by chemical elements that have stable …   Wikipedia

  • Promethium — Prométhium Pour les articles homonymes, voir Pm. Prométhéum …   Wikipédia en Français

  • prométhium — [ prɔmetjɔm ] n. m. • promethium 1953; de Prométhée ♦ Chim. Élément atomique (Pm; no at. 61; m. at. [isotope de plus longue période] 145) du groupe des lanthanides. Tous les isotopes connus du prométhium sont radioactifs. prométhium n. m. CHIM… …   Encyclopédie Universelle

  • promethium — radioactive element, long one of the missing elements, 1948, so called by discoverers Jacob Marinsky and Lawrence Glendenin, who detected it in 1945 in the fusion products of uranium while working on the Manhattan Project. From PROMETHEUS (Cf.… …   Etymology dictionary

  • promethium — ☆ promethium [prō mē′thē əm ] n. [ModL: so named (1949) for earlier prometheum, name proposed by G. M. Coryell for element isolated (1948) by J. A. Marinsky & L. E. Glendenin, U.S. physicists < Gr Promētheus (see PROMETHEUS) in reference to… …   English World dictionary

  • Promethium — Eigenschaften …   Deutsch Wikipedia

  • Prométhium — Pour les articles homonymes, voir Pm. Prométhium Néodyme ← Prométhium → …   Wikipédia en Français

  • promethium — /preuh mee thee euhm/, n. Chem. a rare earth, metallic, trivalent element. Symbol: Pm; at. no.: 61. [1945 50; < NL; see PROMETHEUS, IUM] * * * ▪ chemical element  (Pm), chemical element, only rare earth metal of transition Group IIIb of the… …   Universalium

  • Promethium — Pro|me|thi|um 〈n.; s; unz.; chem. 〉 zu den Metallen der Seltenen Erden gehörendes chem. Element, Ordnungszahl 61 [nach dem grch. Titanen Prometheus] * * * Pro|me|thi|um [nach der griech. Sagengestalt Prometheus; ↑ ium], das; s; Symbol: Pm;… …   Universal-Lexikon

  • Promethium — prometis statusas T sritis fizika atitikmenys: angl. cyclonium; illinium; promethium vok. Promethium, n rus. прометий, m pranc. prométheum, m; prométhium, m …   Fizikos terminų žodynas

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