* Technetium is a member of the transition metals family:
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TECHNETIUM / Tc / 43
When obtained in bulk, technetium is a silvery metal, but it is
more often obtained as a gray powder. It has fair resistance to
oxidation, but will burn in powder form. Somewhat oddly for such
a relatively light element, it has no stable isotopes. The
longest-lived isotope is Tc<98/43>, with a half-life of 4.2
million years.
atomic weight: 98
abundance: negligible
density: ~11.5 gm/cc
melting point: 2,172 C
boiling point: 4,877 C
valence: 2 4 5 6 7
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Technetium was the first "synthetic" element to be discovered. Its isotopes have minor uses as radioactive tracers and the like; it is also useful in the form of the compound potassium pertechnetate(VII) or KTcO4, which can be added to aerated water in closed systems to prevent rust on steel.
