Tungsten

Tungsten, W, is a transition metal element, found in Group VIa of the periodic table.

Atomic Number : 74
Relative Atomic Mass : 183.85

Discovery

Tungsten was discovered by K W Scheele in 1781AD.
Tungsten was isolated by J J y Don Fausto d'Elhuyar in 1783AD.

Occurrence

Tungsten can be found as

Wolframite, (Fe,Mn)WO4,
Scheelite, CaWO4,
Stolzite, PbWO4,
Cuproscheelite, CuWO4, and
Tungstenite, WS2,

Extraction

Tungsten is concentrated using its magnetic properties and then extracted with hydrochloric acid, when a precipitate of tungsten trichloride remains. The latter is dissolved in ammonia and the tungstate formed is crystallised and ignited.

Properties

Tungsten is a hard silvery-white metal, which is stable in air at room temperature.

Reactions

Tungsten resembles Molybdenum in chemical properties.

Uses

Tungsten is used

in making special steel alloys,
for the filaments of electric lamps, and
as the anti-cathode in X-ray tubes.

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