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Oxidation & Electrons | Appearance & Characteristics Reactions | Compounds | Radius | Conductivity Abundance & Isotopes 
Tungsten metal. (Photo: Tomihahndorf) |
General:
| Name: Tungsten | Symbol: W |
| Type: Transition Metal | Atomic weight: 183.85 |
| Density @ 293 K: 19.3 g/cm3 | Atomic volume: 9.53 cm3/mol |
| Discovered: In 1779 Peter Woulfe deduced the existence of a new element - Tungsten - from his analysis of the mineral wolframite (an iron manganese tungstate mineral). Tungsten was isolated by Fausto and Juan Jose de Elhuyar in 1783 by reduction acidified wolframite with charcoal. The element name comes from the Swedish words 'tung sten', meaning heavy stone. The chemical symbol, W, comes from the original name of the element, Wolfram. | |
States
| State (s, l, g): solid | |
| Melting point: 3695 K (3422 oC) | Boiling point: 5823 K (5550 oC) |
Energies
| Specific heat capacity: 0.13 J g-1 K-1 | Heat of atomization: 860 kJ mol-1 |
| Heat of fusion: 35.40 kJ mol-1 | Heat of vaporization : 824.0 kJ mol-1 |
| 1st ionization energy: 770 kJ mol-1 | 2nd ionization energy: 1700 kJ mol-1 |
| 3rd ionization energy: kJ mol-1 | Electron affinity: 78.6 kJ mol-1 |
Oxidation & Electrons
| Shells: 2,8,18,32,12,2 | Electron configuration: [Xe] 4f14 5d4 6s2 |
| Minimum oxidation number: -2 | Maximum oxidation number: 6 |
| Min. common oxidation no.: 0 | Max. common oxidation no.: 6 |
| Electronegativity (Pauling Scale): 2.36 | Polarizability volume: 11.1 Å3 |
Appearance & Characteristics
| Structure: bcc: body-centered cubic | Color: silvery-white |
| Hardness: 7.5 mohs | |
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Harmful effects: Tungsten is considered to be of low toxicity. Characteristics: Tungsten is a very hard, dense, silvery-white, lustrous metal that tarnishes in air, forming a protective oxide coating. In powder form tungsten is gray in color. The metal has the highest melting point of all metals, and at temperatures over 1650 oC also has the highest tensile strength. Pure tungsten is ductile, and tungsten wires, even of a very small diameter, have a very high tensile strength. Tungsten is highly resistant to corrosion. It forms tungstic acid (H2WO4), or wolframic acid from the hydrated oxide (WO3) and its salts are called tungstates, or wolframates. Uses: Tungsten and its alloys are widely used for filaments in older style (not energy saving) electric bulbs and electronic tubes. It is used for making heavy metal alloys because of its hardness. Tungsten is used for high-temperature applications such as welding. High speed steel (which can cut material at higher speeds than carbon steel), contains up to 18% tungsten. Tungsten carbide (WC or W2C) is extremely hard and is used to make drills. It is also used for jewelry because of its hardness and wear resistance. |
Reactions
| Reaction with air: w/ht, ⇒ WO3 | Reaction with 6 M HCl: none |
| Reaction with 15 M HNO3: none | Reaction with 6 M NaOH: |
Compounds
| Oxide(s): WO2, WO3 (tungstic oxide) | Chloride(s): WCl2, WCl4, WCl6 |
| Hydride(s): |
Radius
| Atomic radius: 139 pm | Ionic radius (1+ ion): pm |
| Ionic radius (2+ ion): pm | Ionic radius (3+ ion): pm |
| Ionic radius (2- ion): pm | Ionic radius (1- ion): pm |
Conductivity
| Thermal conductivity: 173 W m-1 K-1 | Electrical conductivity: 18.2 x 10-6 S m-1 |
Abundance & Isotopes
| Abundance earth's crust: 1.25 parts per million by weight, 0.1 parts per million by moles | |
| Abundance solar system: 4 parts per billion by weight, 30 part per trillion by moles | |
| Cost, pure: $11 per 100g | |
| Cost, bulk: $ per 100g | |
| Source: Tunsten is not found free in nature. The principal ores of tungsten are wolframite (an iron manganese tungstate) and scheelite (calcium tungstate, CaWO3). Comercially, the metal is obtained by reducing tungsten oxide with hydrogen or carbon. | |
| Isotopes: Tungsten has 33 isotopes whose half-lives are known with mass numbers from 158 to 190. Of these, three are stable: 180W, 182W, and 186W. | |
