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1.                 From The Elements (07Nov00):
                   
   
   
                   
                     
   radium
   Symbol: Ra
   Atomic number: 88
   Atomic weight: (226)
   Radioactive metallic transuranic element, belongs to group 2 of the
   periodic table. Most stable isotope, Ra-226 has a half-life of 1602
   years,
   which decays into radon. Isolated from pitchblende in 1898 Marie and
   Pierre Curie.