radioactinium

/rey-dee-oh-ak-tin-ee-uhm/US // ˌreɪ di oʊ ækˈtɪn i əm //

放射性内含物,放射性内脏,放射性内酯,放射性内裤

Definitions

n.名词 noun

1
Chemistry.
- : the radioactive isotope of thorium having a mass number 227 and a half-life of 18.8 days. Symbol: RdAc, Th 227