Table
of Properties
|
|
Atomic
Number
|
74
|
|
Atomic
Weight
|
183.86
|
|
Group
Number
|
6
|
|
Electron
Configuration
|
1s2,
2s2, 2p6, 3s2, 3p6, 3d10, 4f14, 5s2, 5p6, 5d4, 6s2
|
|
CAS
Registry Number
|
7440-33-7
|
|
Atomic
Volume
|
9.53
|
|
Lattice
Type
|
Body
Centered Cube
|
|
Lattice
Constant at 20 ºC, Angstroms
|
3.1585
|
|
Natural
Isotopes
|
180,
182, 183, 184, 186
|
|
Density
@ 20 ºC (gm/cc)
|
19.3
|
|
Density
@ 20 ºC (lb./cu. in.)
|
0.697
|
|
Melting
Point ºC
|
3410
|
|
Boiling
Point ºC
|
5530
|
|
Linear
Coefficient of Expansion per ºC
|
4.3
x 10E-6
|
|
Thermal
Conductivity @ 20 ºC (cal/cm/ºC/sec)
|
0.40
|
|
Specific
Heat @ 20 ºC (cal/gram/ºC)
|
0.032
|
|
Electronegativity
(eV) Pauling
|
2.36
|
|
Electronegativity
(eV) Sanderson
|
0.98
|
|
Electronegativity
(eV) Allred Rochow
|
1.40
|
|
Electrical
Conductivity, % IACS
|
31
|
|
Electrical
Resistivity @ 20 ºC (microhm-cm)
|
5.5
|
|
Electrical
Resistivity @ 227 ºC (microhm-cm)
|
10.5
|
|
Electrical
Resistivity @ 727 ºC (microhm-cm)
|
24.3
|
|
Electrical
Resistivity @ 1727 ºC (microhm-cm)
|
55.7
|
|
Electrical
Resistivity @ 2727 ºC (microhm-cm)
|
90.4
|
|
Electrical
Resistivity @ 3227 ºC (microhm-cm)
|
108.5
|
|
Temperature
Coefficient of Electrical Resistivity Per ºC (0 - 100
ºC)
|
0.0046
|
|
Tensile
Strength @ Room Temp., psi
|
100,000
- 500,000
|
|
Tensile
Strength @ 500 ºC, psi
|
75,000
- 200,000
|
|
Tensile
Strength @ 1000 ºC, psi
|
50,000
- 75,000
|
|
Poisson's
Ratio
|
0.284
|
|
Hardness
(Mineral)
|
7.5
|
|
Hardness
(Vickers)
|
3430
|
|
Hardness
(Brinell)
|
2570
|
|
Reflectivity
|
62%
|
|
Total
Emissivity @ 1500 ºC
|
0.23
|
|
Total
Emissivity @ 2000 ºC
|
0.28
|
|
Working
Temperature, ºC
|
<1700
|
|
Recrystallization
Temperature, ºC
|
1300
- 1500
|
