Tungsten (W)
| Symbol | W |
| Atomic Number | 74 |
| Atomic Mass | 183.84 amu |
| Discovered by | Fausto and Juan Jose de Elhuyar, 1783 |
Chemical Properties of Tungsten
| 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 | |
What is Tungsten?
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 (180W, 182W, 183W, 184W, and 186W), 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 sulphides, it occurs as the W4+ cation in the rare mineral tungstenite, WS2 (cf. molybdenite, MoS2).
- Tungsten has essentially anionic geochemistry based on the tungstate WO42- ion, in which the W6+ ion is present in four- or six-fold coordination.
Applications of Tungsten
- Tungsten is an economically important metal, being widely used in light-bulb filaments, electron and television tubes, abrasives and special alloys such as steel tools.
- Tungsten carbide is of great importance to metal-works, in the 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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