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actinium

   Also found in: Medical, Acronyms, Encyclopedia, Wikipedia 0.01 sec.
ac·tin·i·um  (k-tn-m)
n. Symbol Ac1
A radioactive element found in uranium ores, used in equilibrium with its decay products as a source of alpha rays. Its longest lived isotope is Ac 227 with a half-life of 21.6 years. Atomic number 89; melting point 1,050°C; boiling point (estimated) 3,200°C; specific gravity (calculated) 10.07; valence 3. See Table at element.

[From Greek akts, aktn-, ray (from its radioactivity).]

actinium [ækˈtɪnɪəm]
n
(Chemistry / Elements & Compounds) a radioactive element of the actinide series, occurring as a decay product of uranium. It is used as an alpha-particle source and in neutron production. Symbol: Ac; atomic no.: 89; half-life of most stable isotope,227Ac: 21.6 years; relative density: 10.07; melting pt.: 1051°C; boiling pt.: 3200 ± 300°C
[New Latin, from actino- + -ium]

actinium  (k-tn-m)
Symbol Ac
A silvery-white, highly radioactive metallic element of the actinide series that is found in uranium ores. It is about 150 times more radioactive than radium and is used as a source of alpha rays and neutrons. Its most stable isotope has a half-life of about 22 years. Atomic number 89; melting point 1,050°C (1,922°F); boiling point (estimated) 3,200°C (5,792°F); specific gravity (calculated) 10.07; valence 3. See Periodic Table.
ThesaurusLegend:  Synonyms Related Words Antonyms
Noun1.actinium - a radioactive element of the actinide seriesactinium - a radioactive element of the actinide series; found in uranium ores
chemical element, element - any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter
uranium ore - any ore from which uranium can be extracted
Translations
actinium [ækˈtɪnɪəm] Nactinio m


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PacificGMP (San Diego, CA), the leader in single-use bioprocessing for development and manufacturing, entered into a cGMP contract manufacturing agreement with Actinium Pharmaceuticals (Florham Park, NJ), a biopharmaceutical company developing new targeted therapies for cancer.
The topics range from the basic science and research on the actinide series--those 14 chemical elements lying between actinium and nobelium, inclusively, and representing the atomic numbers 89-102 (this group includes such radioactive elements as uranium and plutonium)--to their nuclear and superconducting applications.
Mixed Valency of the Rare Earth and Actinium Ions in Solid States," J.
 
 
 
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