Tantalum is a metal element with the symbol Ta, atomic number 73 and density of 16.68g/cm ³， The melting point is 2980 ℃, which is the third refractory metal after tungsten and rhenium.

Pure tantalum has a slightly blue color and good ductility. It can be rolled into very thin (less than 0.01 mm) plates in a cold state without intermediate annealing.

Tantalum has the same corrosion resistance as glass, and only fluorine, hydrofluoric acid, sulfur trioxide (including fuming sulfuric acid), strong alkali, and certain molten salts have an impact on tantalum at medium temperatures (about 150 ℃). Metal tantalum is stable in room temperature air, and when heated above 500 ℃, it accelerates oxidation to form Ta205. Tantalum has a series of excellent properties, such as high melting point, low steam pressure, good cold working performance, high chemical stability, strong resistance to liquid metal corrosion, and large dielectric constant of surface oxide film. It has important applications in high-tech fields such as electronics, metallurgy, steel, chemical industry, hard alloy, atomic energy, superconducting technology, automotive electronics, aerospace, medical care and scientific research. The current application of tantalum is tantalum capacitors. Tantalum must appear together with niobium with similar chemical properties in nature, and is generally contained in tantalite, niobite and coltan.

Physical properties: The appearance is steel gray, with good resistance to high temperature and corrosion.