Ta, a metallic element, mainly exists in tantalite and coexists with niobium.

Tantalum has moderate hardness and high ductility, and can be drawn into thin foil in the form of fine wires. Its coefficient of thermal expansion is very small. Tantalum has excellent chemical properties and extremely high corrosion resistance. Under both cold and hot conditions, it does not react with hydrochloric acid, concentrated nitric acid, or "aqua regia". It can be used to manufacture evaporating vessels, etc., as well as electrodes, rectifiers and electrolytic capacitor of electronic tubes. Used in medical practice to make thin sheets or threads to repair damaged tissues.

Although tantalum has strong corrosion resistance, its corrosion resistance is due to the formation of a stable tantalum pentoxide protective film on the surface.