The DICT Development Group
2 definitions found
From WordNet (r) 3.0 (2006) :
n 1: a highly unstable radioactive element (the heaviest of the
halogen series); a decay product of uranium and thorium
[syn: astatine, At, atomic number 85]
From The Elements (07Nov00) :
Atomic number: 85
Atomic weight: (210)
Radioactive halogen element. Occurs naturally from uranium and thorium
decay. At least 20 known isotopes. At-210, the most stable, has a
half-life of 8.3 hours. Synthesized by nuclear bombardment in 1940 by
Corson, K.R. MacKenzie and E. Segre at the University of California.
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