actinium


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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 ?
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.
We are delighted to establish a partnership with Actinium Pharmaceuticals and initiate cGMP production for their new Phase I/II clinical trial," said Leigh N.
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.
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 Pharma declared that it has presented an Investigational New Drug (IND) application with the U.
The global market for alpha emitters can be segmented on the basis of radionuclide used (Terbium, Astatine, Bismuth, Actinium, Radium, Lead, Bismuth (Bi-213) and Others), type of medical application (Endocrine tumors, Lymphoma, Bone metastasis, Glioma, Melanoma, Pancreatic Cancer, Ovarian Cancer, Thyroid and Others), on the basis of Geography (North America, Europe, Asia-Pacific, Latin America and Middle East & Africa).
ACTINIUM ([ - 1 + 3] x [20 + 9]) + 14 + 9 + 21 - 13 = 89
The word "radioactivity" was alternatively replaced by the names of the elements occurring in the decay chains of interest, namely uranium, thorium, protactinium, actinium, polonium, bismuth, radon, thallium, and lead.
They also realized that elements like actinium didn't fit into the scheme they'd grown up with.
We believe that Pb does actually not present its true abundance value as existed through stellar element formation, its abundance is increased since it is the end product of the 3 most important decay chains (thorium series, uranium series, actinium series).