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Molybdenum single crystal 42Mo95.94
Isolated in 1781 by P.J. Hjelm at Uppsala, Sweden.
[Greek: lithos = stone]
French: lithium
German: lithium
Italian: litio
Spanish: litio
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Description: Molybdenum is a lustous, silvery metal which is fairly soft when pure. It is usually obtained as a grey powder. It is attacked slowly by acids. It is used in alloys, electrodes and catalysts.
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Metal single crystal properties
| State: |
single crystal |
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| Crystal structure: |
bcc |
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| Production method: |
Floating Zone |
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| Standard size: |
diameter 8-12mm
thickness 1-2mm |
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| Orientation: |
(100), (110) and (111) |
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| Orientation accuracy: |
<2°, <1°, <0.5° or <0.1° |
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| Polishing: |
as cut, one or two sides polished |
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| Roughness of surface: |
<0.03µm |
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| Purity: |
99.99% |
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| Typical analysis (ppm): |
C 10
O 5
N < 5
Al 0.25
Ca 1.5
Cl 1
Co < 1
Fe 10
K 1
Mg 1 |
Ni 1
P 1
S 2.5
Si 5
Ta 1
Ti 0.6
W 25
Zn 0.7
Zr 0.5
Mo balance |
Further Materials properties
| Crystal structure: |
(cell dimensions/pm), space group
b.c.c. (a=314.700), Im3m |
| X-ray diffractions mass absorption coefficients: |
CuKa 162 (µ/r) / cm2g-1
MoKa 18.4 (µ/r) / cm2g-1
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| Neutron scattering length: |
0.6715 b/10-12 cm |
| Thermal neutron capture cross-section: |
2.60 sa / barns
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| Density: |
10.2 g/cm3 |
| Melting point: |
2616.85 °C / 2890 °K |
| Boiling point: |
4611.85 °C / 4885 °K |
| Molar volume: |
9.39 cm3 |
| Thermal conductivity: |
138 [300 K] Wm-1K-1 |
| Coefficient of linear thermal expansion: |
5.43 x 10-6 K-1 |
| Electrical resistivity: |
5.2x10-8 [273 K] Wm |
| Mass magnetic susceptibility: |
+1.2 x 10-8(s) kg-1m3 |
| Young's modulus: |
324.8 GPa |
| Rigidity modulus: |
125.6 GPa |
| Bulk modulus: |
261.2 GPa |
| Poisson's ratio: |
0.293 GPa |
| Radii: |
Mo6+ 62; Mo2+ 92; atomic 136; covalent 129 |
| Electronegativity: |
2.16 (Pauling); 1.30 (Allred); 3.9 eV (absolute) |
| Effective nuclear charge: |
3.45 (Slater); 6.98 (Clementi); 9.95 (Froese-Fischer) |
| Number of Isotopes (incl. nuclear isomers): |
23 |
| Issotope mass range: |
88 -> 106 |
Biological data
| Biological role: |
essential to all species. |
| Toxicity |
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| Toxic intake: |
n.a. |
| Lethal intake: |
LD50 (MoO2, subcutaneous, mouse)=318 mg kg-1 |
| Hazards: |
Animal experiments show molybdenum compunds to be highly toxic and teratogenic, but there is little human data. |
| Level in humans |
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| Blood: |
c. 0.001 mg dm-3 |
| Bone: |
<0.7 p.p.m. |
| Liver: |
1.3 - 5.8 p.p.m. |
| Muscle: |
0.018 p.p.m. |
| Daily dietary intake : |
0.05 - 0.35 mg |
Total mass of element in average
[70 kg] person: |
5 mg |
Geological data
| Minerals: |
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| Mineral |
Formula |
Density |
Hardness |
Crystal apperance |
| Molybdenite |
MoS2 |
4.7 |
1 - 1.5 |
hex. met. grey |
| Wulfenite |
PbMoO4 |
6.78 |
2.7 - 3 |
tet., res. adam. orange |
| Chief ore: |
molybdenite; wulfenite to lesser extent; also obtained as by-product of copper production.
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| World production: |
80 000 tonnes/year |
| Main mining areas: |
USA, Australia, Italy, Norway, Bolivia |
| Reserves: |
5 x 106 tonnes |
| Specimen: |
available as foil, powder rod or wire. Safe.
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| Abundances |
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| Sun: |
145 (relative to H = 1 x 1012) |
| Earth's crust: |
1.5 p.p.m. |
| Seawater: |
0.0100 p.p.m. |
| Residence time:: |
600 000 years |
| Classification: |
accumulating |
| Oxidation state: |
VI |
Other sizes and specifications on request
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