protactinium : Dictionary / Wörterbuch (BEOLINGUS, TU Chemnitz)

English Dictionary: protactinium	by the DICT Development Group
2 results for protactinium
From WordNet (r) 3.0 (2006) [wn]:
protactinium n a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead Synonym(s): protactinium, protoactinium, Pa, atomic number 91
From The Elements (22Oct97) [elements]:
protactinium Symbol: Pa Atomic number: 91 Atomic weight: (231) Radioactive metallic element, belongs to the actinoids. The most stable isotope, Pa-231 has a half-life of 2.43*10^4 years. At least 10 other radioactive isotopes are known. No practical applications are known. Discovered in 1917 by Lise Meitner and Otto Hahn.