THALLIUM (TL)

last update 01 oct 08

* Thallium is a member of the main-group metals family:

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   THALLIUM / Tl / 81

   A soft, silvery-white metal that corrodes easily.  Two isotopes are
   found in nature:  Tl<205/81> (70%) and Tl<203/81> (30%).  Both are
   stable.

     atomic weight:       204.3833
     abundance:           59th
     density:             11.85 g/cc
     melting point:       304 C      
     boiling point:       1,457 C
     valence:             <1> 3
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Thallium is not all that rare, but it has few practical applications, with some use in manufacturing highly refractive glasses, photoelectric cells, and infrared detectors. Production is only a few tens of tonnes a year. It is toxic even in fairly small doses.