Tungsten

  • tungsten, 74w
    wolfram evaporated crystals and 1cm3 cube.jpg
    tungsten
    pronunciationən/ (tung-stən)
    alternative namewolfram, pronounced: əm/ (wuul-frəm)
    appearancegrayish white, lustrous
    standard atomic weight ar, std(w)183.84(1)[1]
    tungsten in the periodic table
    hydrogen helium
    lithium beryllium boron carbon nitrogen oxygen fluorine neon
    sodium magnesium aluminium silicon phosphorus sulfur chlorine argon
    potassium calcium scandium titanium vanadium chromium manganese iron cobalt nickel copper zinc gallium germanium arsenic selenium bromine krypton
    rubidium strontium yttrium zirconium niobium molybdenum technetium ruthenium rhodium palladium silver cadmium indium tin antimony tellurium iodine xenon
    caesium barium lanthanum cerium praseodymium neodymium promethium samarium europium gadolinium terbium dysprosium holmium erbium thulium ytterbium lutetium hafnium tantalum tungsten rhenium osmium iridium platinum gold mercury (element) thallium lead bismuth polonium astatine radon
    francium radium actinium thorium protactinium uranium neptunium plutonium americium curium berkelium californium einsteinium fermium mendelevium nobelium lawrencium rutherfordium dubnium seaborgium bohrium hassium meitnerium darmstadtium roentgenium copernicium nihonium flerovium moscovium livermorium tennessine oganesson
    mo

    w

    sg
    tantalumtungstenrhenium
    atomic number (z)74
    groupgroup 6
    periodperiod 6
    blockd-block
    element category  transition metal
    electron configuration[xe] 4f14 5d4 6s2[2]
    electrons per shell2, 8, 18, 32, 12, 2
    physical properties
    phase at stpsolid
    melting point3695 k ​(3422 °c, ​6192 °f)
    boiling point6203 k ​(5930 °c, ​10706 °f)
    density (near r.t.)19.3 g/cm3
    when liquid (at m.p.)17.6 g/cm3
    heat of fusion52.31 kj/mol[3][4]
    heat of vaporization774 kj/mol
    molar heat capacity24.27 j/(mol·k)
    vapor pressure
    p (pa) 1 10 100 1 k 10 k 100 k
    at t (k) 3477 3773 4137 4579 5127 5823
    atomic properties
    oxidation states−4, −2, −1, 0, +1, +2, +3, +4, +5, +6 (a mildly acidic oxide)
    electronegativitypauling scale: 2.36
    ionization energies
    • 1st: 770 kj/mol
    • 2nd: 1700 kj/mol
    atomic radiusempirical: 139 pm
    covalent radius162±7 pm
    color lines in a spectral range
    spectral lines of tungsten
    other properties
    natural occurrenceprimordial
    crystal structurebody-centered cubic (bcc)
    body-centered cubic crystal structure for tungsten
    speed of sound thin rod4620 m/s (at r.t.) (annealed)
    thermal expansion4.5 µm/(m·k) (at 25 °c)
    thermal conductivity173 w/(m·k)
    electrical resistivity52.8 nΩ·m (at 20 °c)
    magnetic orderingparamagnetic[5]
    magnetic susceptibility+59.0·10−6 cm3/mol (298 k)[6]
    young's modulus411 gpa
    shear modulus161 gpa
    bulk modulus310 gpa
    poisson ratio0.28
    mohs hardness7.5
    vickers hardness3430–4600 mpa
    brinell hardness2000–4000 mpa
    cas number7440-33-7
    history
    discoverycarl wilhelm scheele (1781)
    first isolationjuan josé elhuyar and fausto elhuyar (1783)
    named bytorbern bergman (1781)
    main isotopes of tungsten
    iso­tope abun­dance half-life (t1/2) decay mode pro­duct
    180w 0.12% 1.8×1018 y α 176hf
    181w syn 121.2 d ε 181ta
    182w 26.50% stable
    183w 14.31% stable
    184w 30.64% stable
    185w syn 75.1 d β 185re
    186w 28.43% stable
    category category: tungsten
    | references

    tungsten, or wolfram,[7][8] is a chemical element with the symbol w and atomic number 74. the name tungsten comes from the former swedish name for the tungstate mineral scheelite, tungsten which means "heavy stone".[9] tungsten is a rare metal found naturally on earth almost exclusively combined with other elements in chemical compounds rather than alone. it was identified as a new element in 1781 and first isolated as a metal in 1783. its important ores include wolframite and scheelite.

    the free element is remarkable for its robustness, especially the fact that it has the highest melting point of all the elements discovered, melting at 3422 °c (6192 °f, 3695 k). it also has the highest boiling point, at 5930 °c (10706 °f, 6203 k).[10] its density is 19.25 times that of water, comparable with that of uranium and gold, and much higher (about 1.7 times) than that of lead.[11] polycrystalline tungsten is an intrinsically brittle[12][13] and hard material (under standard conditions, when uncombined), making it difficult to work. however, pure single-crystalline tungsten is more ductile and can be cut with a hard-steel hacksaw.[14]

    tungsten's many alloys have numerous applications, including incandescent light bulb filaments, x-ray tubes (as both the filament and target), electrodes in gas tungsten arc welding, superalloys, and radiation shielding. tungsten's hardness and high density give it military applications in penetrating projectiles. tungsten compounds are also often used as industrial catalysts.

    tungsten is the only metal from the third transition series that is known to occur in biomolecules that are found in a few species of bacteria and archaea. it is the heaviest element known to be essential to any living organism.[15] however, tungsten interferes with molybdenum and copper metabolism and is somewhat toxic to more familiar forms of animal life.[16][17]

  • characteristics
  • history
  • occurrence
  • chemical compounds
  • production
  • applications
  • biological role
  • health factors
  • patent claim
  • see also
  • references
  • external links

Tungsten, 74W
Wolfram evaporated crystals and 1cm3 cube.jpg
Tungsten
Pronunciationən/ (TUNG-stən)
Alternative namewolfram, pronounced: əm/ (WUUL-frəm)
Appearancegrayish white, lustrous
Standard atomic weight Ar, std(W)183.84(1)[1]
Tungsten in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
Mo

W

Sg
tantalumtungstenrhenium
Atomic number (Z)74
Groupgroup 6
Periodperiod 6
Blockd-block
Element category  Transition metal
Electron configuration[Xe] 4f14 5d4 6s2[2]
Electrons per shell2, 8, 18, 32, 12, 2
Physical properties
Phase at STPsolid
Melting point3695 K ​(3422 °C, ​6192 °F)
Boiling point6203 K ​(5930 °C, ​10706 °F)
Density (near r.t.)19.3 g/cm3
when liquid (at m.p.)17.6 g/cm3
Heat of fusion52.31 kJ/mol[3][4]
Heat of vaporization774 kJ/mol
Molar heat capacity24.27 J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 3477 3773 4137 4579 5127 5823
Atomic properties
Oxidation states−4, −2, −1, 0, +1, +2, +3, +4, +5, +6 (a mildly acidic oxide)
ElectronegativityPauling scale: 2.36
Ionization energies
  • 1st: 770 kJ/mol
  • 2nd: 1700 kJ/mol
Atomic radiusempirical: 139 pm
Covalent radius162±7 pm
Color lines in a spectral range
Spectral lines of tungsten
Other properties
Natural occurrenceprimordial
Crystal structurebody-centered cubic (bcc)
Body-centered cubic crystal structure for tungsten
Speed of sound thin rod4620 m/s (at r.t.) (annealed)
Thermal expansion4.5 µm/(m·K) (at 25 °C)
Thermal conductivity173 W/(m·K)
Electrical resistivity52.8 nΩ·m (at 20 °C)
Magnetic orderingparamagnetic[5]
Magnetic susceptibility+59.0·10−6 cm3/mol (298 K)[6]
Young's modulus411 GPa
Shear modulus161 GPa
Bulk modulus310 GPa
Poisson ratio0.28
Mohs hardness7.5
Vickers hardness3430–4600 MPa
Brinell hardness2000–4000 MPa
CAS Number7440-33-7
History
DiscoveryCarl Wilhelm Scheele (1781)
First isolationJuan José Elhuyar and Fausto Elhuyar (1783)
Named byTorbern Bergman (1781)
Main isotopes of tungsten
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct
180W 0.12% 1.8×1018 y α 176Hf
181W syn 121.2 d ε 181Ta
182W 26.50% stable
183W 14.31% stable
184W 30.64% stable
185W syn 75.1 d β 185Re
186W 28.43% stable
Category Category: Tungsten
| references

Tungsten, or wolfram,[7][8] is a chemical element with the symbol W and atomic number 74. The name tungsten comes from the former Swedish name for the tungstate mineral scheelite, tungsten which means "heavy stone".[9] Tungsten is a rare metal found naturally on Earth almost exclusively combined with other elements in chemical compounds rather than alone. It was identified as a new element in 1781 and first isolated as a metal in 1783. Its important ores include wolframite and scheelite.

The free element is remarkable for its robustness, especially the fact that it has the highest melting point of all the elements discovered, melting at 3422 °C (6192 °F, 3695 K). It also has the highest boiling point, at 5930 °C (10706 °F, 6203 K).[10] Its density is 19.25 times that of water, comparable with that of uranium and gold, and much higher (about 1.7 times) than that of lead.[11] Polycrystalline tungsten is an intrinsically brittle[12][13] and hard material (under standard conditions, when uncombined), making it difficult to work. However, pure single-crystalline tungsten is more ductile and can be cut with a hard-steel hacksaw.[14]

Tungsten's many alloys have numerous applications, including incandescent light bulb filaments, X-ray tubes (as both the filament and target), electrodes in gas tungsten arc welding, superalloys, and radiation shielding. Tungsten's hardness and high density give it military applications in penetrating projectiles. Tungsten compounds are also often used as industrial catalysts.

Tungsten is the only metal from the third transition series that is known to occur in biomolecules that are found in a few species of bacteria and archaea. It is the heaviest element known to be essential to any living organism.[15] However, tungsten interferes with molybdenum and copper metabolism and is somewhat toxic to more familiar forms of animal life.[16][17]