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Pronunciation | (TUNG-stən) |
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Alternative name | wolfram, pronounced: (WUUL-frəm) |
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Allotropes | α-tungsten (common), β-tungsten |
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Appearance | grayish white, lustrous |
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| 183.84(1)[1] |
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Atomic number (Z) | 74 |
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Group | group 6 |
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Period | period 6 |
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Block | d-block |
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Electron configuration | [Xe] 4f14 5d4 6s2[2] |
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Electrons per shell | 2, 8, 18, 32, 12, 2 |
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Phase at STP | solid |
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Melting point | 3695 K (3422 °C, 6192 °F) |
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Boiling point | 6203 K (5930 °C, 10706 °F) |
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Density (near r.t.) | 19.25 g/cm3 |
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when liquid (at m.p.) | 17.6 g/cm3 |
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Heat of fusion | 52.31 kJ/mol[3][4] |
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Heat of vaporization | 774 kJ/mol |
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Molar heat capacity | 24.27 J/(mol·K) |
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Vapor pressure
P (Pa) |
1 |
10 |
100 |
1 k |
10 k |
100 k |
at T (K) |
3477 |
3773 |
4137 |
4579 |
5127 |
5823 |
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Oxidation states | −4, −2, −1, 0, +1, +2, +3, +4, +5, +6 (a mildly acidic oxide) |
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Electronegativity | Pauling scale: 2.36 |
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Ionization energies | - 1st: 770 kJ/mol
- 2nd: 1700 kJ/mol
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Atomic radius | empirical: 139 pm |
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Covalent radius | 162±7 pm |
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Spectral lines of tungsten |
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Natural occurrence | primordial |
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Crystal structure | body-centered cubic (bcc) |
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Speed of sound thin rod | 4620 m/s (at r.t.) (annealed) |
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Thermal expansion | 4.5 µm/(m⋅K) (at 25 °C) |
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Thermal conductivity | 173 W/(m⋅K) |
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Electrical resistivity | 52.8 nΩ⋅m (at 20 °C) |
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Magnetic ordering | paramagnetic[5] |
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Molar magnetic susceptibility | +59.0×10−6 cm3/mol (298 K)[6] |
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Young's modulus | 411 GPa |
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Shear modulus | 161 GPa |
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Bulk modulus | 310 GPa |
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Poisson ratio | 0.28 |
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Mohs hardness | 7.5 |
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Vickers hardness | 3430–4600 MPa |
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Brinell hardness | 2000–4000 MPa |
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CAS Number | 7440-33-7 |
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Discovery and first isolation | Juan José Elhuyar and Fausto Elhuyar[7] (1783) |
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Named by | Torbern Bergman (1781) |
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Symbol | "W": from Wolfram, originally from Middle High German wolf-rahm 'wolf's foam' describing the mineral wolframite[8] |
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Main isotopes |
Decay |
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abundance |
half-life (t1/2) |
mode |
product |
180W |
0.120% |
1.8×1018 y |
α |
176Hf |
181W |
synth |
121.2 d |
ε |
181Ta |
182W |
26.5% |
stable |
183W |
14.3% |
stable |
184W |
30.6% |
stable |
185W |
synth |
75.1 d |
β− |
185Re |
186W |
28.4% |
stable |
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Category: Tungsten | references |