Tantalum is a metallic element with an atomic number of 73 and the chemical symbol Ta. The element's corresponding monomer is a steel-gray metal that is highly resistant to corrosion, both in cold and hot conditions, and does not react to hydrochloric acid, concentrated nitric acid or "aqua regia".
Tantalum is found mainly in tantalite, symbiotically with niobium. Tantalum is moderately hard [1], ductile, and can be drawn into a thin, filamentary foil. Its coefficient of thermal expansion is very small. Tantalum has excellent chemical properties and is highly resistant to corrosion. Can be used to manufacture evaporator vessels, etc., can also do the electrode of the tube, rectifier, electrolytic capacitors. Medically it is used to make thin sheets or fine wires to mend damaged tissue. Although tantalum is highly resistant to corrosion, its corrosion resistance is due to the generation of a stable protective film of tantalum pentoxide (Ta₂O₅) on the surface.
