Astatine

2 definitions found

From WordNet (r) 2.0 [wn]:

  astatine
       n : a highly unstable radioactive element (the heaviest of the
           halogen series); a decay product of uranium and thorium
           [syn: {At}, {atomic number 85}]

From Elements database 20001107 [elements]:



  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.