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Tungsten, W

Tungsten, also called wolfram, is a chemical element that has the symbol W (German: Wolfram) and atomic number 74. A very hard, heavy, steel-gray to white transition metal, tungsten is found in several ores including wolframite and scheelite and is remarkable for its robust physical properties, especially the fact that it has the highest melting point of all the non-alloyed metals and the second highest of all the elements after carbon. The pure form is used mainly in electrical applications but its many compounds and alloys are widely used in many applications, most notably in light bulb filaments, in X-ray tubes (as both the filament and target), and in superalloys. Tungsten is the only metal from the third transition series that is known to occur in biomolecules.

Technical Data
Symbol	W	Density (20°C)/gcm³³	19.3
Atomic number	74	Melting point /°C	-3380
No. of naturally occurring isotopes	5	Boiling point /°C	-5500
Atomic weight	183.85(+/-0.03)	ΔH_fus/kJmol^-1	-35
Electronic configuration	[Xe]4f¹⁴5d⁴6s¹	ΔH_vap/kJmol^-1	824(+/-21)
Metal radius(12-coordinate)/pm	139	ΔH_{f(monoatomic gas)}/kJmol^-1	849(+/-13)
Ionic radius(6-coordinate)/pm VI	60	Ionization energy/kJmol^-1I	770
Ionic radius(6-coordinate)/pm V	62	Ionization energy/kJmol^-1II	1700
Ionic radius(6-coordinate)/pm IV	66	Ionization energy/kJmol^-1III	2300
Electrical resistivity (20°C)/μohm cm	~5	Electronegativity χ	1.7

Evaporation Techniques
Temperature (^oC) @Vap. Pressure			Techniques				Remarks
10^-8 Torr	10^-6 Torr	10^-4 Torr	Electron Beam	Crucible	Coil	Boat	Remarks
2117	2407	2757	Good	-	-	-	Forms volatile oxides. Films hard & adherent

Evaporation Materials
T9-5000-M pellets 6mm diameter x 3mm long
T9-5001-M pellets 6mm diameter x 6mm long
T9-5002-M pellets 12mm diameter x 6mm long
T9-5003-M pieces 1-3mm
T9-5011-M pellets 3mm diameter x 3mm long
T9-5012-M pieces 3-20mm

The foils are available in either rectangular or circular shape. Please enter width and length or diameter of the required foil.

Foil
T9-3003-F 0.004" (0.1mm)
T9-3007-F 0.008" (0.2mm)

Powder
T9-10003-P -325 mesh
T9-10004-P 10 microns average
T9-10006-P <1 micron average

Sheet
T9-4001-S 0.015" (0.38mm)
T9-4002-S 0.020" (0.5mm)
T9-4003-S 0.030" (0.76mm)
T9-4004-S 0.040" (1mm)
T9-4006-S 0.060" (1.5mm)
T9-4008-S 0.125" (3.175mm)
T9-4009-S 0.250" (6.35mm)
T9-4010-S 0.375" (9.525mm)
T9-4011-S 0.500" (12.7mm)
T9-4012-S 0.750" (19.05mm)
T9-4013-S 1" (25.4mm)

Wire
T9-1003-W 0.004" (0.1mm) annealed
T9-1009-W 0.010" (0.254mm)
T9-1012-W 0.020" (0.5mm)
T9-1014-W 0.040" (1.0mm) as drawn
T9-1014-W1 0.040" (1.0mm) annealed, stress-relieved

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