What is the definition of Actinium? | Dictionary.net

ACTINIUM

\aktˈɪni͡əm], \aktˈɪni‍əm], \a_k_t_ˈɪ_n_iə_m]\

Definitions of ACTINIUM

2010 - Medical Dictionary Database
1919 - The concise Oxford dictionary of current English

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Actinium. A trivalent radioactive element and the prototypical member of the actinide family. It has the atomic symbol Ac, atomic number 89, and atomic weight 227.0278. Its principal isotope is 227 and decays primarily by beta-emission.

2010 - Medical Dictionary Database
By DataStellar Co., Ltd

Radio-active substance found in pitchblende; an element that turns dark in sunlight. [Greek]

1919 - The concise Oxford dictionary of current English
By Sir Augustus Henry

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