Tantalum was discovered in 1802 by Anders Gustaf Ekeberg. The metal was named after Tantalus from Greek mythology. It belongs to a group of refractory metals which are characterised by higher melting point and density, and low vapour pressure and thermal coefficient of expansion. Tantalum has a high electrical capacitance.

Due to its high level of ductility, tantalum is very suitable for forming processes, such as bending, stamping, pressing or deep-drawing, and is very difficult to use machining processes with tantalum. While its tensile strength and hardness increase with cold working, this simultaneously causes the material's breaking elongation to fall. Although the material loses ductility, it does not become brittle. Even small quantities of interstitially dissolved elements, such as oxygen, nitrogen, hydrogen and carbon, are able to modify mechanical properties of tantalum. In addition, purities of tantalum powder, individual processing methods and conditions used also influence its mechanical properties. Tantalum's modulus of elasticity is lower than that of tungsten and molybdenum and resembles that of pure iron. Tantalum offers excellent weldability compared to tungsten and molybdenum.

Tantalum is the most corrosion resistant among the refractory metals, for instance, resistant to most acids and bases at room temperature. When exposed to air, tantalum forms a very dense oxide layer (Ta2O5) which protects the base material from aggression. This oxide layer therefore makes tantalum highly corrosion-resistant. However, the corrosion resistance of tantalum falls gradually with increasing temperature. Tantalum does not react with noble gases. As a result, high purity noble gases can be used as protective gases. However, with increasing temperature, tantalum reacts strongly with oxygen or air and may absorb large quantities of hydrogen and nitrogen. Annealing tantalum in a high vacuum gets rid of these impurities.