: a shiny radioactive metallic element of relatively short life see Chemical Elements Table
Example Sentences
Recent Examples on the WebThese natural uranium isotopes decay into the element thorium, which in turn decays into protactinium, and each has its own isotopes. Artemis Spyrou, The Conversation, 24 May 2022
Word History
Etymology
New Latin
First Known Use
1918, in the meaning defined above
Medical Definition
protactinium
noun
prot·ac·tin·i·um ˌprōt-ˌak-ˈtin-ē-əm
variants also protoactinium
ˌprōt-ō-
: a shiny metallic radioelement of relatively short life—symbol Pa see Chemical Elements Table