At high temperatures, tantalum becomes much more reactive. The element has a melting point exceeded only by tungsten and rhenium. Tantalum is used to make a variety of alloys with desirable properties such as high melting point, high strength, good ductility, etc. Scientists at Los Alamos have produced a tantalum carbide graphite composite material, which is said to be one of the hardest materials ever made. The metal is also widely used to fabricate chemical process equipment, nuclear reactors, and aircraft and missile parts.
Tantalum is completely immune to body liquids and is a nonirritating metal.
It has, therefore, found wide use in making surgical appliances. Tantalum oxide is used to make special glass with high index of refraction for camera lenses. The metal has many other uses. Environmental Fate Occurs almost invariably along with niobium.