WHAT IS TUNGSTEN?
Tungsten , or wolfram, is a chemical element with the symbol W and atomic number 74. The name tungsten comes from the former Swedish name for the tungstate mineral scheelite , tungsten which means "heavy stone". Tungsten is a rare metal found naturally on Earth almost exclusively combined with other elements in chemical compounds rather than alone. It was identified as a new element in 1781 and first isolated as a metal in 1783. Its important ores include wolframite and scheelite .
The free element is remarkable for its robustness, especially the fact that it has the highest melting point of all the elements discovered, melting at 3,422 °C (6,192 °F; 3,695 K). It also has the highest boiling point , at 5,930 °C (10,710 °F; 6,200 K). Its density is 19.25 times that of water, comparable with that of uranium and gold , and much higher (about 1.7 times) than that of lead. Polycrystalline tungsten is an intrinsically brittle and hard material (under standard conditions, when uncombined), making it difficult to work . However, pure single-crystalline tungsten is more ductile and can be cut with a hard-steel hacksaw.
Tungsten's many alloys have numerous applications, including incandescent light bulb filaments, X-ray tubes (as both the filament and target), electrodes in gas tungsten arc welding , superalloys , and radiation shielding . Tungsten's hardness and high density give it military applications in penetrating projectiles . Tungsten compounds are also often used as industrial catalysts.
