radio-actinium
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Actinium — (pronEng|ækˈtɪniəm) is a radioactive chemical element with the symbol Ac and atomic number 89, which was discovered in 1899, the earliest discovered of the radioactive elements.CharacteristicsActinium is a silvery, radioactive, metallic element.… … Wikipedia
ACTINIUM — L’existence dans la pechblende de l’actinium, élément radioactif de numéro atomique 89, fut établie en 1899 par André Louis Debierne, collaborateur de Pierre et Marie Curie qui venaient, un an auparavant, de découvrir, dans ce minerai d’uranium,… … Encyclopédie Universelle
Actinium — Eigenschaften … Deutsch Wikipedia
Radio-isotope — Radioisotope Les radioisotopes, radionucléides ou radioéléments, contraction de radioactivité et d isotope, sont des atomes dont le noyau est instable et donc radioactif. Cette instabilité peut être due à un excès de protons, de neutrons ou des… … Wikipédia en Français
actinium — n. rare radio active element … Dictionary of difficult words
Radioactinium — Radio|actinium, ältere Bezeichnung für das radioaktive Thoriumisotop 227Th (Symbol RaAc), Zwischenglied in der Uran Actinium Reihe (Radioaktivität). * * * Ra|dio|ac|ti|ni|um, das (Chemie): radioaktives Isotop des Thoriums … Universal-Lexikon
radioactinium — “+ noun Etymology: New Latin, from radio + actinium : the radioactive isotope of thorium of mass number 227 formed by disintegration of actinium symbol RdAc or Th227; see actinium series * * * /ray dee oh ak t … Useful english dictionary
Isotopes of thorium — Although thorium (Th) has multiple isotopes, none of these isotopes are stable; however, one isotope is relatively stable (232Th). As such, thorium is considered to be mononuclidic. It has a characteristic terrestrial isotopic composition and… … Wikipedia
radioactinium — /ray dee oh ak tin ee euhm/, n. Chem. the radioactive isotope of thorium having a mass number 227 and a half life of 18.8 days. Symbol: RdAc, Th 227 [1905 10; RADIO + ACTINIUM] * * * … Universalium
Actinide — The atomic bomb dropped on Nagasaki had a plutonium charge.[1] The actinide or actinoid (IUPAC nomenclature) series encompasses the 15 metallic chemical elements with atomic numbers from 89 to 103, actinium thro … Wikipedia
