actinium

[æk'tɪnɪəm] n

actinium 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 [æk'tɪnɪəm] n

environ.

aktinoidy

English thesaurus

Actinium [æk'tɪnɪəm] abbr.

abbr., scottish