actinium


Also found in: Thesaurus, Medical, Acronyms, Encyclopedia, Wikipedia.

ac·tin·i·um

 (ăk-tĭn′ē-əm)
n. Symbol Ac
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 21.77 years. Atomic number 89; melting point 1,050°C; boiling point 3,198°C; specific gravity (calculated) 10.07; valence 3. See Periodic Table.

[From Greek aktīs, aktīn-, ray (from its radioactivity); see nekw-t- in Indo-European roots.]

actinium

(ækˈtɪnɪəm)
n
(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
[C19: New Latin, from actino- + -ium]

ac•tin•i•um

(ækˈtɪn i əm)

n.
a radioactive, silver-white, metallic element that glows blue in the dark, resembling the rare earths in chemical behavior and valence. Symbol: Ac; at. no.: 89; at. wt.: 227.
[< French (1900); see actino-, -ium2]

ac·tin·i·um

(ăk-tĭn′ē-əm)
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. Its most stable isotope has a half-life of about 22 years. Atomic number 89. See Periodic Table.
ThesaurusAntonymsRelated WordsSynonymsLegend:
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
актиний
actinium
actinium
aktiinium
aktinium
aktinij
aktínium
aktín
アクチニウム
actinium
aktinis
actinium
aktyn
actiniu
aktinij
aktinium
aktinyum

actinium

[ækˈtɪnɪəm] Nactinio m
References in periodicals archive ?
I am very excited to join the Actinium organization," said Dr.
Schaffer offers the example of metal actinium, whose isotope 225Ac has demonstrated the potential to kill cancerous tumours, although it would need to be employed in combination with biochemical agents that could prevent it from accumulating in other parts of the body.
Actinium may sell USD15m worth of stock and may keep the offering open until end-January 2013, it said.
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.
From actinium to zirconium, this marvelous encyclopedia details all 115 elements of the periodic table to reveal the nature of each and its relationship to us.
In 1917, however, the German physical chemist Otto Hahn (1879-1968) and a co-worker, Austrian physicist Lise Meitner (1878-1968), discovered a truly new element that disintegrated into actinium (see 1899).
As chemists we must conclude that instead of radium, actinium, and thorium, we must substitute the symbols barium, lanthanum, and cerium, and as nuclear chemists who are acquainted with nuclear physics, we find this a very difficult conclusion to reach, and it might be that some combination of circumstances has led us to an erroneous conclusion here".
Actinium Pharmaceuticals highlighted its progress and activity at the recently concluded BMT Tandem Meetings, the combined annual meetings of the American Society of Blood and Marrow Transplantation and the Center for International Blood & Marrow Transplant Research.
Biopharmaceutical company Actinium Pharmaceuticals (NYSE MKT:ATNM) said on Tuesday that it has filed an application with the European Medicines Agency (EMA) seeking orphan designation for Actimab-A for patients newly diagnosed with acute myeloid leukemia (AML).
I therefore suggest changing the graph shown to replace Bohrium by Iron and Actinium by Cerium.