At that time, he first discovered tungstenic acid, which could be obtained from the scheelite, and predicted that it would be possible to reduction-oxidation the acid to obtain new metal elements.
In 1783, brothers Jose Elhuyar, Fausto Elhuyar discovered the same material in a hubnelite(MnWO₄), which was redox to charcoal and discovered pure tungsten.
The symbol W, atomic number 74, is called tungsten or wolfram.
The word 'tungsten' means 'heavy stone' in Swedish.
Heavy, very hard, transition metals are produced from ore such as hubnelite and cheelite.
Pure tungsten has a silver-gray gloss. It is hard and ductile, easy to process.
A small amount of impurity makes tungsten firm, but it has a brittle disadvantage.
Tungsten is the highest melting point among the elements, the melting point is 3422℃ and is also the element with the lowest vapor pressure above 1650℃. (although carbon dissolves at the hisest point, sublimate at 4027℃), the density is 19.3g/cm³, simillar to gold or uranium.
(Body centered cubic lattice) (A15 phases)
Tensile strength is the highest of all elements. This is because 5d orbital electrons strongly bind tungsten atoms together.
It has two types of atomic attangements. α tungsten is the body centered cubic lattice and is the most stable of the tungsten structures. The electrical resistance is 1/3 of β tungsten and the critical point of superconductors is approximately 0.015k.
β tungsten has an A15 phases structure and is metastable. The critical point is 1~4K.
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