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Discovered in 1901 by E.-A. Demarcay at Paris, France.
[Named after Europe]
French: europium
German: Europium
Italian: europio
Spanish: europio
Description: Europium is a soft, silvery metal which is one of the rarest of the so-called rare earth group (more correctly termed the lanthanides). It is the most reactive of these metals, reacting quickly with oxygen and water. It is little used, but some employed in thin-film superconductor alloys.
Crystal structure: |
(cell dimensions/pm), space group, |
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X-ray diffractions mass absorption coefficients: | CuKa 425 (µ/r) / cm2g-1 MoKa 61.5 (µ/r) / cm2g-1 |
Neutron scattering length: | 0.722 b/10-12 cm |
Thermal neutron capture cross-section: | 4600 sa / barns |
Density: | 5243 kg/m-3 [293 K] |
Melting point: | 821,85°C / 1095°K |
Boiling point: | 1596,85°C / 1870°K |
Molar volume: | 28.98 cm3 |
Thermal conductivity: | 13.9 [300 K] W m-1K-1 |
Coefficient of linear thermal expansion: | 32 x 10-6 K-1 |
Electrical resistivity: | 990.0 x 10-8 [298 K] Ωm |
Mass magnetic susceptibility: | +2.81 x 10-6(s) kg-1m3 |
Young's modulus: | 18.2 GPa |
Rigidity modulus: | 7.9 GPa |
Bulk modulus: | 8.3 GPa |
Poisson's ratio: | 0.152 GPa |
Radi: | Eu3+ 98;Eu2+ 112; atomic 204; covalent 185 |
Electronegativity: | n.a. (Pauling); 1.01 (Allred); ≤3.1 eV (absolute) |
Effective nuclear charge: | 2.85 (Slater); 8.11 (Clementi); 11.17 (Froese-Fischer) |
Number of Isotopes (incl. nuclear isomers): | 26 |
Isotope mass range: | 141 -> 160 |
Biological role: | None. |
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Toxicity | |
Toxic intake: | n.a. |
Lethal intake: | LD50 (nitrate, oral, mouse) > 5000 mg Kg-1 |
Hazards: | Europium is mildly toxic by ingestion. |
Level in humans | n.a. but very low |
Blood: | n.a. |
Bone: | n.a. |
Liver: | n.a. |
Muscle: | n.a. |
Daily dietary intake: | n.a. |
Total mass of element in average [70 kg] person: |
n.a. but very low |
Minerals: | ||||
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Mineral | Formula | Density | Hardness | Crystal apperance |
Bastnäsite-Ce* | (Ce, La, etc.) CO3F | 4.9 | 4 - 4.5 | hex., vit/ greasy yellow |
Monazite-Ce* | (Ce, La, Nd, Th, etc.)PO4 | 5.20 | 5 - 5.5 | mon., waxy/ vit. yellow-brown |
* Although not a major constituent, europium is present in extractable amounts.
Chief ores: | monazite, bastnäsite |
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World production: | c. 400 tonnes/year |
Main mining areas: | USA, Brazil, India, Sri Lanka, Australia, China |
Reserves: | c. 1.5 x 106 tonnes |
Specimen: | available as ingots. Safer. |
Abundances | |
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Sun: | 5 (relative to H = 1 x 1012) |
Earth's crust: | 2.1 ppm |
Seawater | |
Altantic surface: | 0.9 x 10-7 ppm |
Atlantic deep: | 1.5 x 10-7 ppm |
Pacific surface: | 1.0 x 10-7 ppm |
Pacific deep: | 2.7 x 10-7 ppm |
Residence time: | 500 years |
Classification: | recycled |
Oxidation state: | III |
Source: Emsley, J. (1998) The Elements (3rd Edition)
Other sizes and specifications on request