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| Atomic symbol: W |
| Atomic number: 74 |
| Atomic weight: 183.85 |
| Atomic volume: 9.53 cm3/mol |
| Density: 19.3 g/cm3 |
| Period Number: 6 |
| Group number: 6 |
| Group name: Trans. Met. |
| Element classification: Metal |
| Phase at room temperature: Solid |
| Melting Point: 3683.2 K |
| Boiling point: 5773 K |
| Heat of fusion: 35.40 kJ/mol |
| Heat of vaporization: 824.0 kJ/mol |
| Ionization Energy: 7.98 eV |
| 1st ionization energy: 770 kJ/mole |
| 2nd ionization energy: kJ/mole |
| 3rd ionization energy: kJ/mole |
| Electronegativity: 2.36 |
| Electron affinity: 78.6 kJ/mole |
| Specific heat: 0.13 J/gK |
| Heat atomization: 849 kJ/mole atoms |
| Shells: 2,8,18,32,12,2 |
| Electron Shell Configuration: [Xe] 4f14 5d4 6s2 |
| Minimum oxidation number: -2 |
| Maximum oxidation number: 6 |
| Minimum common oxidation number: 0 |
| Maximum common oxidation no: 6 |
Appearance & Characteristics |
| Structure:: bcc: body-centered cubic |
| Color: bluish-gray |
| Hardness: mohs |
| Toxicity: ? |
| Characteristics: highest melting metal |
| Uses: WC drill bits, bulb wire |
| Reaction with air: none, w/ht =>WO3 |
| Reaction with 6M HCl: none |
| Reaction with 15M HNO3: none |
| Reaction with 6M NaOH: ? |
| Number of isotopes: 5 |
| Oxide(s): WO2 WO3 |
| Hydride(s): ? |
| Chloride(s): WClx [x=2-6] |
| Atomic Radius: 139 pm |
| Ionic radius (1- ion): pm |
| Ionic radius (1+ ion): pm |
| Ionic radius (2- ion): pm |
| Ionic radius (2+ ion): pm |
| Ionic radius (3+ ion): pm |
| Thermal conductivity: 173 J/m-sec-deg |
| Electrical conductivity: 176.991 1/mohm-cm |
| Polarizability: 11.1 A^3 |
| Source: Scheelite,wolframite(oxide) |
| Relative abundance solar system: -0.876 log |
| Abundance earth's crust: 0.2 log |
| Estimated crustal abundance: 1.25 milligrams per kilogram |
| Estimated oceanic abundance: 1×10-4 milligrams per liter |
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| (Swedish, tung sten: heavy stone) In 1779 Peter Woulfe examined the mineral now known as wolframite and concluded it must contain a new substance. Scheele, in 1781, found that a new acid could be made from tungsten (a name first applied about 1758 to a mineral now known as scheelite). Scheele and Berman suggested the possibility of obtaining a new metal by reducing this acid. The de Elhuyar brothers found acid in wolframite in 1783 that was identical to the acid of tungsten (tungstic acid) of Scheele, and in that year they succeeded in obtaining the element by reduction of this acid with charcoal. Tungsten occurs in wolframite, scheelite, huebnertie, and ferberite. Important deposits of tungsten occur in California, Colorado, South Korea, Bolivia, Russia, and Portugal. China is reported to have about 75% of the world's tungsten resources. Natural tungsten contains five stable isotopes. Twenty one other unstable isotopes are recognized. The metal is obtained commercially be reducing tungsten oxide with hydrogen or carbon. |
| Pure tungsten is a steel-gray to tin-white metal. Very pure tungsten can be cut with a hacksaw, forged, spun, drawn, and extruded. The impure metal is brittle and can be worked only with difficulty. Tungsten has the highest melting point of all metals, and at temperatures over 16500C has the highest tensile strength. The metal oxidizes in air and must be protected at elevated temperatures. It has excellent corrosion resistance and is attacked only slightly by most mineral acids. The thermal expansion is about the same as borosilicate glass, which makes the metal useful for glass-to-metal seals. |
| Tungsten and its alloys are used extensively for filaments for electric lamps, electron and television tubes, and for metal evaporation work; for electrical contact points for automobile distributors; X-ray targets; windings and heating elements for electrical furnaces; and for numerous spacecraft and high-temperature applications. High-speed tool steels, Hastelloy(R), Stellite(R), and many other alloys contain tungsten. Tungsten carbide is of great importance to the metal-working, mining, and petroleum industries. Calcium and magnesium tungstates are widely used in fluorescent lighting; other salts of tungsten are used in the chemical and tanning industries. Tungsten disulfide is a dry, high-temperature lubricant, stable to 500C. Tungsten bronzes and other tungsten compounds are used in paints. Tungsten powder (99.9%) costs about $50/lb. |
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