Introduction
Group: 6 or VI B
Atomic Weight: 183.84
Period: 6
CAS Number: 7440-33-7
Classification
No Stable Isotopes
Solid
Liquid
Gas
Solid (Predicted)
Description • Uses/Function
In 1779 Peter Woulfe examined the mineral now known as wolframite and concluded it must contain a newsubstance. Scheele, in 1781, found that a new acid could be made from tung sten (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 an acid in wolframitein 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 ofthis acid with charcoal. Tungsten occurs in wolframite, (Fe, Mn)WO4; scheelite, CaWO4; huebnerite, MnWO4; and ferberite, FeWO4. Importantdeposits of tungsten occur in California, Colorado, South Korea, Bolivia, Russia, and Portugal. China is reported to have about 75% of the world’stungsten resources. Natural tungsten contains five stable isotopes. Thirty two other unstable isotopes and isomers are recognized. The metal is obtainedcommercially by reducing tungsten oxide with hydrogen or carbon. Pure tungsten is a steel-gray to tin-white metal. Very pure tungsten can be cut witha hacksaw, and can be forged, spun, drawn, and extruded. The impure metal is brittle and can be worked only with difficulty. Tungsten has the highestmelting point of all metals, and at temperatures over 1650°C has the highest tensile strength. The metal oxidizes in air and must be protected at elevatedtemperatures. It has excellent corrosion resistance and is attacked only slightly by most mineral acids. The thermal expansion is about the same asborosilicate 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 andheating 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 andmagnesium tungstates are widely used in fluorescent lighting; other salts of tungsten are used in the chemical and tanning industries. Tungsten disulfideis a dry, high-temperature lubricant, stable to 500°C. Tungsten bronzes and other tungsten compounds are used in paints. Tungsten powder (99.95%)costs about $325/kg. 1
• "Wolfram has the highest melting point, 3370°C, of any of the metals. It is on this accoun that the wolfram filaments of light bulbs can be raised without melting to a temperature at which it emits an intense white light.
Wolfram is produced in the form of a gray powder. One of the earliest triumphs of powder metallurgy was the conversion of this powder in the electric furnace into an ingot which could be formed into a rod by hammering and then drawn through an electrically heated die into the exceedingly fine filament seen in our incandescent lamps. The atoms in this filament have arranged themselves in a crystal lattice structure.
Wolfram is used as a substitute for platinum in electric contact points and terminals for spark gaps, also for wiring electric furnaces and as targets for X-ray tubes. It is an important constituent of alloy steels." 2
• "A number of transition metals (Ti, Zr, Hf, V, Nb, Ta, Mo, W) form interstitial carbides of composition MC and, in some cases, M2C. These carbides have extremely high melting points; they are very hard, and they are good electrical conductors." 3
Physical Properties
Melting Point:4* 3422 °C = 3695.15 K = 6191.6 °F
Electron Configuration: [Xe] 6s2 4f14 5d4
n = 5
Electronegativity (Pauling scale):6 1.7
Specific Heat: 0.132 J/g°C 10 = 24.267 J/mol°C = 0.032 cal/g°C = 5.800 cal/mol°C
Earth - Source Compounds: oxides 16
External Links:
Journals:
(1) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:33.
Boiling Point:4* 5555 °C = 5828.15 K = 10031 °F
Sublimation Point:4
Triple Point:4
Critical Point:4
Density:5 19.3 g/cm3
* - at 1 atm
Electron Configuration
Block: d
Highest Occupied Energy Level: 6
Valence Electrons:
Quantum Numbers:
ℓ = 2
mℓ = 1
ms = +½
Bonding
Electropositivity (Pauling scale): 2.3
Electron Affinity:7 0.815 eV
Oxidation States: +6,4
Work Function:8 4.55 eV = 7.2891E-19 J
Ionization Potential
eV 9
kJ/mol
Ionization Potential
eV 9
kJ/mol
Ionization Potential
eV 9
kJ/mol
1
7.864
758.8
Thermochemistry
Thermal Conductivity: 174 (W/m)/K, 27°C 11
Heat of Fusion: 35.4 kJ/mol 12 = 192.6 J/g
Heat of Vaporization: 824 kJ/mol 13 = 4482.2 J/g
State of Matter
Enthalpy of Formation (ΔHf°)14
Entropy (S°)14
Gibbs Free Energy (ΔGf°)14
(kcal/mol)
(kJ/mol)
(cal/K)
(J/K)
(kcal/mol)
(kJ/mol)
(s)
0
0
7.81
32.67704
0
0
(ℓ)
11.22
46.94448
10.92
45.68928
9.66
40.41744
(g)
203.4
851.0256
41.55
173.8452
193.3
808.7672
Isotopes
Nuclide
Mass 15
Half-Life 15
Nuclear Spin 15
Binding Energy
158W
157.97456(54)#
1.37(17) ms
0+
1,245.32 MeV
159W
158.97292(43)#
8.2(7) ms
7/2-#
1,253.39 MeV
160W
159.96848(22)
90(5) ms
0+
1,270.77 MeV
161W
160.96736(21)#
409(16) ms
7/2-#
1,278.85 MeV
162W
161.963497(19)
1.36(7) s
0+
1,286.92 MeV
163W
162.96252(6)
2.8(2) s
3/2-#
1,294.99 MeV
164W
163.958954(13)
6.3(2) s
0+
1,312.37 MeV
165W
164.958280(27)
5.1(5) s
3/2-#
1,320.45 MeV
166W
165.955027(11)
19.2(6) s
0+
1,328.52 MeV
167W
166.954816(21)
19.9(5) s
3/2-#
1,336.59 MeV
168W
167.951808(17)
51(2) s
0+
1,344.66 MeV
169W
168.951779(17)
76(6) s
(5/2-)
1,352.73 MeV
170W
169.949228(16)
2.42(4) min
0+
1,370.12 MeV
171W
170.94945(3)
2.38(4) min
(5/2-)
1,378.19 MeV
172W
171.94729(3)
6.6(9) min
0+
1,386.26 MeV
173W
172.94769(3)
7.6(2) min
5/2-
1,394.33 MeV
174W
173.94608(3)
33.2(21) min
0+
1,402.40 MeV
175W
174.94672(3)
35.2(6) min
(1/2-)
1,410.47 MeV
176W
175.94563(3)
2.5(1) h
0+
1,418.55 MeV
177W
176.94664(3)
132(2) min
1/2-
1,426.62 MeV
178W
177.945876(16)
21.6(3) d
0+
1,434.69 MeV
179W
178.947070(17)
37.05(16) min
(7/2)-
1,442.76 MeV
180W
179.946704(4)
STABLE
0+
1,450.83 MeV
181W
180.948197(5)
121.2(2) d
9/2+
1,458.90 MeV
182W
181.9482042(9)
STABLE
0+
1,466.97 MeV
183W
182.9502230(9)
STABLE
1/2-
1,465.73 MeV
184W
183.9509312(9)
STABLE
0+
1,473.80 MeV
185W
184.9534193(10)
75.1(3) d
3/2-
1,481.87 MeV
186W
185.9543641(19)
STABLE
0+
1,489.94 MeV
187W
186.9571605(19)
23.72(6) h
3/2-
1,498.02 MeV
188W
187.958489(4)
69.78(5) d
0+
1,506.09 MeV
189W
188.96191(21)
11.6(3) min
(3/2-)
1,504.84 MeV
190W
189.96318(18)
30.0(15) min
0+
1,512.91 MeV
191W
190.96660(21)#
20# s [>300 ns]
3/2-#
1,520.99 MeV
192W
191.96817(64)#
10# s [>300 ns]
0+
1,529.06 MeV
Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses. 15
Abundance
Earth - Seawater: 0.0001 mg/L 17
Earth -
Crust:
1.25 mg/kg = 0.000125% 17
Earth -
Total:
180 ppb 18
Mercury -
Total:
139 ppb 18
Venus -
Total:
189 ppb 18
Chondrites - Total: 0.12 (relative to 106 atoms of Si) 19
Compounds
tungsten(II) bromide
tungsten(II) chloride
tungsten(II) iodide
tungsten(III) bromide
tungsten(III) chloride
tungsten(III) iodide
tungsten(IV) bromide
tungsten(IV) carbide
tungsten(IV) chloride
tungsten(IV) fluoride
tungsten(IV) oxide
tungsten(IV) selenide
tungsten(IV) silicide
tungsten(IV) sulfide
tungsten(IV) telluride
tungsten(V) bromide
tungsten(V) chloride
tungsten(V) fluoride
tungsten(V) oxytribromide
tungsten(V) oxytrichloride
tungsten(VI) chloride
tungsten(VI) dioxydibromide
tungsten(VI) dioxydichloride; tungsten dichloride dioxide
tungsten(VI) dioxydiiodide
tungsten(VI) fluoride
tungsten(VI) oxide; tungsten trioxide
tungsten(VI) oxytetrabromide
tungsten(VI) oxytetrachloride
tungsten(VI) oxytetrafluoride
tungsten(VI) sulfide
Safety Information
Material Safety Data Sheet - ACI Alloys, Inc.
For More Information
American Elements
Chemical & Engineering News
Chemical Elements
ChemGlobe
Chemicool
Environmental Chemistry
(1) Gumbsch, Riedle, Hartmaier and Fischmeister, Science 282, 1293-1295 (1998)
(2) John Trowbridge and Samuel Sheldon, Proc. Am. Acad. Arts Sci. 24, 181-184 (1889)
Sources
(2) - Brownlee, Raymond B., Fuller, Robert W., and Whitsit, Jesse E. Elements of Chemistry; Allyn and Bacon: Boston, Massachusetts, 1959; pp 560-1.
(3) - Jolly, William L. The Chemistry of the Non-Metals; Prentice-Hall: Englewood Cliffs, New Jersey, 1966; p 119.
(4) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:132.
(5) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 4:39-4:96.
(6) - Dean, John A. Lange's Handbook of Chemistry, 11th ed.; McGraw-Hill Book Company: New York, NY, 1973; p 4:8-4:149.
(7) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 10:147-10:148.
(8) - Speight, James. Lange's Handbook of Chemistry, 16th ed.; McGraw-Hill Professional: Boston, MA, 2004; p 1:132.
(9) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 10:178 - 10:180.
(10) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:133.
(11) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:193, 12:219-220.
(12) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:123-6:137.
(13) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:107-6:122.
(14) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(15) - Atomic Mass Data Center. http://amdc.in2p3.fr/web/nubase_en.html (accessed July 14, 2009).
(16) - Silberberg, Martin S. Chemistry: The Molecular Nature of Matter and Change, 4th ed.; McGraw-Hill Higher Education: Boston, MA, 2006, p 965.
(17) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 14:17.
(18) - Morgan, John W. and Anders, Edward, Proc. Natl. Acad. Sci. USA 77, 6973-6977 (1980)
(19) - Brownlow, Arthur. Geochemistry; Prentice-Hall, Inc.: Englewood Cliffs, NJ, 1979, pp 15-16.