|Group||6||Melting point||3414°C, 6177°F, 3687 K|
|Period||6||Boiling point||5555oC,10031oF, 5828 K|
|Block||d||Density (g cm−3)||19.3|
|Atomic number||74||Relative atomic mass||183.84|
|State at 20°C||Solid||Key isotopes||182W, 184W, 186W,|
|Electron configuration||[Xe] 4f145d46S2||CAS number||7440-33-7|
|ChemSpider ID||22403||ChemSpider is a free chemical database|
- Tungsten, also known as wolfram, along with Cr and Mo, belongs to group 6 of the periodic table. The element has an atomic number of 74 and an atomic mass of 184. Its two main oxidation states are +4 & +6 and five stable isotopes (180 W, 182 W, 183 W, 184 W and 186 W), among of which 182 W, 184 W, and 186 W are the most abundant at 26.498%, 30.64%, and 28.426% respectively. Tungsten is similar to Molybdenum chemically and its chemistry is amongst the most complex of the transition elements.
- Tungsten is a relatively rare element, with a crystal abundance of around 1.0–1.5 mg kg-1, similar to that of its neighboring elements in the periodic table, Molybdenum.
- Tungsten is a strong lithophile element, although it is a siderophile in iron meteorites and is markedly less chalcophile than Molybdenum. Apart from sulfides, it occurs as the W4+ cation in the rare mineral tungstenite, WS2 (cf. molybdenite, MoS2). Tungsten has an essentially anionic geochemistry based on the tungstate WO4 2- ion, in which the W6+ ion is present in four- or six-fold coordination.
- Tungsten is an economically important metal, being widely used in light-bulb filaments, electron and television tubes, abrasives and special alloys such as steels tool. Tungsten carbide is of great importance to metal-works, in mining and petroleum industries. Contamination from these sources is therefore possible in industrial and urban areas.
- Evidence for a significant biological role for Tungsten is sparse, in contrast to Molybdenum, which is an essential trace element, although minor concentrations in some plants suggest a specialized function perhaps substituting for Molybdenum when there is a deficiency. There is limited ecotoxicity data available, anything higher than trace amounts of Tungsten in solution is generally considered to be toxic.
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