Tantalum

"Tantalum ( /ˈtæntələm/ tan-təl-əm) is a chemical element with the symbol Ta and atomic number 73. Previously known as tantalium, the name comes from Tantalus, a character from Greek mythology.^[3] Tantalum is a rare, hard, blue-gray, lustrous transition metal that is highly corrosion resistant. It is part of the refractory metals group, which are widely used as minor component in alloys. The chemical inertness of tantalum makes it a valuable substance for laboratory equipment and a substitute for platinum, but its main use today is in tantalum capacitors in electronicequipment such as mobile phones, DVD players, video game systems and computers. Tantalum, always together with the chemically similarniobium, occurs in the minerals tantalite, columbite and coltan (a mix of columbite and tantalite)."

"Tantalum is dark (blue-gray),^[16] dense, ductile, very hard, easily fabricated, and highly conductive of heat and electricity. The metal is renowned for its resistance to corrosion by acids; in fact, at temperatures below 150 °C tantalum is almost completely immune to attack by the normally aggressive aqua regia. It can be dissolved with hydrofluoric acid or acidic solutions containing the fluoride ion and sulfur trioxide, as well as with a solution of potassium hydroxide. Tantalum's high melting point of 3017 °C (boiling point 5458 °C) is exceeded only by tungsten, rhenium andosmium for metals, and carbon."