astatine

2 definitions found

astatine - WordNet (r) 2.1 (2005) :

  astatine
      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]

astatine - Elements (07Nov00) :

  astatine
  Symbol: At
  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
  D.R.
  Corson, K.R. MacKenzie and E. Segre at the University of California.