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Discovered in 1886 by C.A. Winkler at Freiberg, Germany.
[Latin, Germania= Germany]
French: germanium
German: Germanium
Italian: germanio
Spanish: germanio
Description: Ultrapure germanium is a silvery-white brittle metalloid element. It is stable in air and water, is unaffected by acids, expect HNO3, and alkalis. It is used in semiconductors, alloys and special glasses for infrared devices.
Crystal structure: |
(cell dimensions/pm), space group, |
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X-ray diffractions mass absorption coefficients: | CuKa 75.6 (µ/r) / cm2g-1 MoKa 64.8 (µ/r) / cm2g-1 |
Neutron scattering length: | 0.8193 b/10-12 cm |
Thermal neutron capture cross-section: | 2.2 sa / barns |
Density: | 5323 kg/m-3 [293 K]; 5490 [liquid at m.p.] |
Melting point: | 937.45°C / 1210.6°K |
Boiling point: | 2829.85°C / 3103°K |
Molar volume: | 13.64 cm3 |
Thermal conductivity: | 59.9 [300 K] W m-1K-1 |
Coefficient of linear thermal expansion: | 5.57 x 10-6 K-1 |
Electrical resistivity: | 0.46 [295 K] Ωm |
Mass magnetic susceptibility: | -1.328 x 10-9(s) kg-1m3 |
Young's modulus: | 79.9 GPa |
Rigidity modulus: | 29.6 GPa |
Bulk modulus: | n.a. |
Poisson's ratio: | 0.32 GPa |
Radi: | Ge2+ 90; Ge4- 272; atomic 123; covalent 122 |
Electronegativity: | 2.01 (Pauling); 2.02 (Allred); 4.6 eV (absolute) |
Effective nuclear charge: | 5.65 (Slater); 6.78 (Clementi); 7.92 (Froese-Fischer) |
Number of Isotopes (incl. nuclear isomers): | 24 |
Isotope mass range: | 64-> 83 |
Biological role: | None, but germanium acts to stimulate metabolism. |
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Toxicity | |
Toxic intake: | Germanium salts gernerally have low toxicity |
Lethal intake: | LD50 (various, ingestion, rats etc.) = 500 - 5000 mg Kg-1 |
Hazards: | The fumes of GeCl, liquid can irritate the eyes and lungs |
Level in humans | |
Blood: | c 0.44 ppm |
Bone: | n.a. |
Liver: | 0.15 ppm |
Muscle: | 0.14 ppm |
Daily dietary intake: | 0.4 - 1.5 mg |
Total mass of element in average [70 kg] person: |
5 mg |
Minerals: | ||||
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Mineral | Formula | Density | Hardness | Crystal apperance |
Germanite | Cu26Fe4Ge2S32 | 4.46 | 4 | cub, met. pale greyish-pink |
Chief ores: | not mined as such: widely distributed in other minerals and Ge is recovered as a by-product of zinc and copper refining |
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World production: | 80 tonnes/year |
Main mining areas: | see copper and zinc. |
Reserves: | n. a. |
Specimen: | available as chips, pieces or powder. Safe. |
Abundances | |
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Sun: | 3160 (relative to H = 1 x 1012) |
Earth's crust: | 1.8 ppm |
Seawater | |
Atlantic surface: | 0.07 x 10-6 ppm |
Atlantic deep: | 0.14 x 10-6 ppm |
Pacific surface: | 0.35 x 10-6 ppm |
Pacific deep: | 7.00 x 10-6 ppm |
Residence time: | 20 000 years |
Classification: | recycled |
Oxidation state: | IV |
Source: Emsley, J. (1998) The Elements (3rd Edition)
Other sizes and specifications on request