Wir sind führender Hersteller und Lieferant von Forschungsmaterialien
1755 von Joseph Black in Edinburgh, Schottland, als Element erkannt; 1808 von Sir Humphry Davy dargestellt.
[Griechisch, Magnesia = Gebiet in Thessalien]
French: magnésium
English: magnesium
Italian: magnesio
Spanish: magnesio
Beschreibung: Silberweißes, glänzendes, relativ weiches Material. Darzustellen durch Elektrolyse von MgCl2-Schmelzen. Verbrennt in Luft und reagiert mit heißem Wasser. Verwendet als Metall und in leichten Legierungen für Motoren, auch für reaktive Elektroden, um Metalle zu schützen, die Seewasser ausgesetzt sind.
State: | single crystal |
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Crystal structure: | hexagonal |
Production method: | Bridgman |
Standard size: | diameter 10-20mm thickness 1-2 |
Orientation: | (0001), (1-100) and (11-20) |
Orientation accuracy: | <2°, <1°, <0.4° or <0.1° |
Polishing: | as cut, one or two sides polished |
Roughness of surface: | <0.03µm |
Purity: | 99.999% |
Typical analysis (ppm): | C 3 H < 1 O 9 N < 5 Cu 1.60 Fe 1.80 Ni < 1 Pb 0.30 Si 0.30 Ga, Hf and Ta are below the detection limit |
Density: | 1.74 g/cm3 |
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Melting point: | 648.85 °C / 922.0 °K |
Boiling point: | 1089.85 °C / 1363 °K |
Molar volume: | 13.98 cm3 |
Thermal conductivity: | 156 [300 K] Wm-1K-1 |
Coefficient of linear thermal expansion: | 26.1 x 10-6 K-1 |
Electrical resistivity: | 4.38x 10-8 [293 K] Wm |
Mass magnetic susceptibility: | +6.8 x 10-9(s) kg-1m3 |
Young's modulus: | 44.7 GPa |
Rigidity modulus: | 17.3 GPa |
Bulk modulus: | 35.6 GPa |
Poisson's ratio: | 0.291 GPa |
Radii: | Mg2+ 79; atomic 160; covalent 136 |
Electronegativity: | 1.31 (Pauling); 1.23 (Allred); 3.75 eV (absolute) |
Effective nuclear charge: | 2.85 (Slater); 3.31 (Clementi); 4.15 (Froese-Fischer) |
Number of Isotopes (incl. nuclear isomers): | 12 |
Issotope mass range: | 20 -> 31 |
Crystal structure, (cell dimentions / pm), space group | hexagonal |
X-ray diffraction: mass absorption coefficients: | CuKα 38.6 (µ/r) / cm2g-1 MoKα 4.11 (µ/r) / cm2g-1 |
Neutron scattering length: | 0.5375 b/10-12 cm |
Thermal neutron capture cross-section: | 0.063 sa / barns |
Biological role: | Essential to all species |
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Toxicity | |
Toxic intake: | low toxicity |
Lethal intake: | LD50 (chloride, oral, rat)=8100 mg kg-1 |
Hazards: | Magnesium compounds vary in toxicity but there is no evidence that magnesium itself produces systemic poisoning. |
Level in humans | |
Blood: | 37.8 mg dm-3 |
Bone: | 700 - 1800 p.p.m. |
Liver: | 590 p.p.m. |
Muscle: | 900 p.p.m. |
Daily dietary intake: | 250 - 380 mg |
Total mass of element in average [70 kg] person: | 19 g |
Mineral | Formula | Density | Hardness | Crystal apperance |
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Brucite | Mg(OH)2 | 2.39 | 2.5 | rhom., waxy/vit. white |
Carnallite | KMgCl3 | 1.602 | 2.5 | orth., greasy, colourless reddish |
Cordierite | Mg2Al4Si5O18 | 2.57 | 7 | orth., translucent grey/lilac etc. |
Diopside | CaMgSi2O6 | 3.3 | 5.5 - 6.5 | mon., vit./resinous white/yellow |
Dolomite | CaMg(CO3)2 | 2.85 | 3.4 - 4 | rhom., vit. colourless |
Enstatite | Mg2Si2O6 | 3.209 | 6 - 6 | orth., pearly/vit., colourless grey |
Chief ore: | seawater; and teh ores dolomite, magnestite; carnallite, kieserite and brucite |
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World production: | 325000 tonnes/year |
Main mining areas: | Austria, China, Poland, Russia, USA, India, Greece, Cananda |
Reserves: | >2 x 1010 tonnes as ores ; and >1 x 1024 tonnes in the sea |
Specimen: | available as chips, granules, powder, ribbon, rod or turnings. Safe. |
Abundances | |
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Sun: | 4.0 x 107 (relative to H = 1 x 1012) |
Earth's crust: | 23000 p.p.m. |
Seawater: | |
Residence time: | |
Classification: | accumulating |
Oxidation state: | II |