A rare, radioactive, metallic chemical element, one of the actinides, found in pitchblende: symbol, Pa; at. no. 91
a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead
Find another word for protoactinium. In this page you can discover 3 synonyms, antonyms, idiomatic expressions, and related words for protoactinium, like: protactinium, p.a. and atomic number 91.