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Tungsten |
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Pronunciation | (TUNG-stən) |
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Appearance | riach, lustrous |
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Standard atomic weight Ar, std(W) | 7002183840000000000♠183.84(1)[1] |
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Tungsten in the periodic cairt |
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Mo ↑ W ↓ Sg |
tantalum ← tungsten → rhenium |
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Atomic nummer (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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Element category | Transeetion metal |
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Electron confeeguration | [Xe] 4f14 5d4 6s2[2] |
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Electrons per shell | 2, 8, 18, 32, 12, 2 |
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Pheesical properties |
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Phase at STP | solit |
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Meltin pynt | 3695 K (3422 °C, 6192 °F) |
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Bylin pynt | 5828 K (5555 °C, 10031 °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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Creetical pynt | 13892 K, MPa |
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Heat o fusion | 35.3 kJ/mol |
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Heat o vapourisation | 806.7 kJ/mol |
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Molar heat capacity | 24.27 J/(mol·K) |
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Vapour pressur
P (Pa) |
1 |
10 |
100 |
1 k |
10 k |
100 k |
at T (K) |
3477 |
3773 |
4137 |
4579 |
5127 |
5823 |
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Atomic properties |
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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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Atomic radius | empirical: 139 pm |
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Covalent radius | 162±7 pm |
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Spectral lines o tungsten |
Ither properties |
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Naitural occurrence | primordial |
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Creestal structur | body-centred cubic (bcc) |
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Speed o soond thin rod | (annealed) 4620 m/s (at r.t.) |
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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 n Ω·m (at 20 °C) |
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Magnetic orderin | paramagnetic[3] |
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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 haurdness | 7.5 |
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Vickers haurdness | 3430 MPa |
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Brinell haurdness | 2570 MPa |
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CAS Nummer | 7440-33-7 |
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History |
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Diskivery | Torbern Bergman (1781) |
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First isolation | Juan José Elhuyar an Fausto Elhuyar (1783) |
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Main isotopes o tungsten |
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Isotope |
Abundance |
Hauf-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% |
>1.7×1020 y |
(α) |
178Hf |
183W |
14.31% |
>8×1019 y |
(α) |
179Hf |
184W |
30.64% |
>1.8×1020 y |
(α) |
180Hf |
185W |
syn |
75.1 d |
β− |
185Re |
186W |
28.43% |
>4.1×1018 y |
(α) |
182Hf |
(β−β−) |
186Os |
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Decay modes in parentheses are predictit, but hae nae yet been observed |
| references |