protactinium
nounUK /ˌpɹəʊ.tækˈtɪn.i.əm/ · US /ˌpɹoʊ.tækˈtɪn.i.əm/
Etymology From proto- + actinium.
1
A chemical element (symbol Pa) with atomic number 91. A dense, silvery-gray actinide metal.
- Synonyms
- protoactinium
- Derived terms
- diprotactinium, eka-protactinium, protactinate
- Related terms
- actinium