Aktinyum 1899 yılında André-Louis Debierne tarafından keşfedilmiştir.
- Actinium was discovered by André-Louis Debierne in 1899.
Aktinyum radyoaktif bir elementtir.
- Actinium is a radioactive element.
... and not act in terms of short-term political interest. ...
... Governments, in part, are supposed to be there to act in ...