Tungsten Information
Scroll Down To Download
Tungsten Element
Tungsten, or wolfram,[8][9] 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".[10] 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).[11] 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.[12] Polycrystalline tungsten is an intrinsically
brittle[13][14] 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.[15]
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.
Tungsten is the only metal from the third transition series that
is known to occur in biomolecules that are found in a few species of bacteria
and archaea. It is the heaviest element known to be essential to any living
organism.[16] However, tungsten interferes with molybdenum and copper
metabolism and is somewhat toxic to more familiar forms of animal life.
Sources
Most tungsten resources are found in China, South Korea,
Bolivia, Great Britain, Russia and Portugal, as well as in California and
Colorado. Though it is found in these many places, 80 percent of world’s supply
is controlled by China, according to the BBC.
The element naturally occurs in the minerals scheelite,
wolframite, huebnertie and ferberite. It is harvested from the minerals by
reducing tungsten oxide with hydrogen or carbon.
Once it is sourced, tungsten is often mixed into alloys. The
hardest alloys are shaped using diamonds. Diamonds are the only things harder
than some tungsten alloys.
Movies ColdStar is The Best
Website/Platform For Hollywood HD Movies. We Provide Direct Download Links For
Fast And Secure Downloading. Just Click On Download Button.
Comments
Post a Comment