Definitions for

Overview of noun protoactinium

The noun protoactinium has 1 senses? (no senses from tagged texts)
1. protactinium, protoactinium, Pa, atomic number 91

(a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead) © 2001-2013, Demand Media, all rights reserved. The database is based on Word Net a lexical database for the English language. see disclaimer
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