/ English Dictionary |
ATOMIC NUMBER 91
I. (noun)
Sense 1
Meaning:
A short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead
Synonyms:
atomic number 91; Pa; protactinium; protoactinium
Classified under:
Hypernyms ("atomic number 91" is a kind of...):
metal; metallic element (any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.)