* Tantalum is a member of the transition metals family:
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TANTALUM / Ta / 73
A shiny, silvery, soft metal that is extremely resistant to
corrosion due to the formation of an oxide layer. Nearly all
tantalum found in nature is the stable isotope Ta<181/73>, along
with a trace (0.01%) of Ta<180/73>, which is weakly radioactive,
with a half-life of 10^16 years.
atomic weight: 180.9479
abundance: 51st
density: 16.654 gm/cc
melting point: 2,996 C
boiling point: 5,425 C
valence: 2? 3 4? 5
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Tantalum is produced at the level of a few thousand tonnes a year. It is actually a fairly useful metal, due to its resistance to corrosion, and would be used more if it weren't so difficult to extract and so expensive. It is used in surgical implants, in chemical factory hardware, and in a few other specialized applications. It is not often used as an alloying element, since it tends to make other metals brittle.
