* Radium is a member of the alkaline earth metals family:
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RADIUM / Ra / 88
A soft, silvery, lustrous, very radioactive metal. Over two dozen
isotopes are known, all unstable, the longest-lived being
Ra<226/88>, with a half-life of 1,620 years. It is found in nature
since it is part of a decay series, as are the other two naturally
occurring isotopes, Ra<223/88> -- with a half-life of 11.5 days
-- and Ra<224/88> -- with a half-life of 3.7 days.
atomic weight: 226.0254
abundance: 86th
density: 5 gm/cc
melting point: 700 C
boiling point: 1,140 C
valence: 2
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Radium has traditionally been used as the active component of luminous paint for watches and dials, though in an era of electronic watches and displays that use is of little importance.
