Tantalum [Ta, 73]

Tantalum (Ta), a blue-gray transition metal of group 5 in the periodic table of elements, is hard and highly corrosion resistant. Tantalum is resistant to corrosion and to several chemical attacks. For this reason, it has been employed in chemical industries, especially where strong acids are vaporized. The mean Ta content of soils worldwide is estimated to be 1.1 mg/kg. Tantalum content in the human body (70 kg) is about 0.2 mg. The pure metal is, to a great degree, inert both in vivo and in vitro. The pure metal and its oxides possess low solubility and toxicity. Tantalum has been in clinical use since before 1940, and has found a wide range of diagnostic and implant applications. It is highly resistant to chemical attack and arouses very little adverse biological response in both reduced or oxidized forms. Tantalum is very biocompatible in a variety of applications, including bone surgery.