Aktinyum 1899 yılında André-Louis Debierne tarafından keşfedilmiştir.
- Actinium was discovered by André-Louis Debierne in 1899.
Aktinyum-224'ün yarı ömrü 2.7 saattir.
- The half life of actinium-224 is 2.7 hours.
... Governments, in part, are supposed to be there to act in ...
... Act in terms of what's going to be good for all of us over ...