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Tungsten - W General Information Discovery Tungsten was discovered by J.J. and F. Elhuijar in 1783 in Vergara, Spain. However, in 1779 Woulfe examined the mineral wolframite and concluded it must contain a new element. An alternative name for tungsten is wolfram, from this discovery. Appearance Tungsten metal is silvery-white and lustrous, but the element is usually obtained as a grey powder. Source The principal tungsten containing ores are scheelite and wolframite. Commercially, the metal is obtained by reducing tungsten oxide with hydrogen or carbon. Uses Tungsten and its alloys are used extensively for filaments for electric lamps, electron tubes and television tubes. As it has the highest melting point of all metals it is used in numerous high-temperature applications. High-speed tool steels contain tungsten, as does a new "painless" dental drill which spins at ultra-high speeds. Tungsten carbide is of great importance to the metal-working, mining and petroleum industries. Calcium and magnesium tungstates are widely used in fluorescent lighting. Biological Role Tungsten has no known biological role, and has low toxicity. General Information Tungsten has the highest melting point and lowest vapour pressure of all metals, and at temperatures over 1650K has the highest tensile strength. The metal resists attack by oxygen, acids and alkalis. |
| Physical Information | |||
| Atomic Number | 74 | ||
| Relative Atomic Mass (12C=12.000) | 183.85 | ||
| Melting Point/K | 3680 | ||
| Boiling Point/K | 5930 | ||
| Density/kg m-3 | 19300 (293K) | ||
| Ground State Electron Configuration | [Xe]4f145d46s2 | ||
| Electron Affinity(M-M-)/kJ mol-1 | 119 |
| Key Isotopes | ||||||
| nuclide | 180W | 182W | 183W | 184W | 185W | |
| atomic mass | 179.9 | 181.9 | 182.9 | 183.9 | ||
| natural abundance | 0.10% | 26.3% | 14.3% | 30.7% | 0% | |
| half-life | stable | stable | stable | stable | 75 days | |
| nuclide | 186W | 187W | ||||
| atomic mass | 185.9 | |||||
| natural abundance | 28.6% | 0% | ||||
| half-life | stable | 23.9 h | ||||
| Other Information | ||
| Enthalpy of Fusion/kJ mol-1 | 35.2 | |
| Enthalpy of Vaporisation/kJ mol-1 | 824.2 | |
| Oxidation States | ||
| W-IV, W-II, W-I, WO, WII, WIII, WIV, WV, WVI | ||
| Covalent Bonds /kJ mol-1 | ||
| not applicable | ||
| Ionisation Energies/kJ mol-1 | ||
| M - M+ | 770 | |
| M+ - M2+ | 1700 | |
| M2+ - M3+ | 2300 | |
| M3+ - M4+ | 3400 | |
| M4+ - M5+ | 4600 | |
| M5+ - M6+ | 5900 | |
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