Actinium
From Simple English Wikipedia, the free encyclopedia
Actinium is chemical element 89 on the periodic table. Its symbol is Ac. Actinium's mass is 227 g/mol.
Actinium is a silver radioactive metal. It is so radioactive that it glows in the dark. Even a small amount of actinium is dangerous to people.
Actinium was discovered in 1899 by André-Louis Debierne, a French chemist.