Strontium 38Sr87.62
Strontium was recognized as an element in 1790 by A. Crawford at Edingburg, Schottland. Isolated in 1808 by Sir Humphry Davy at London, England.
[Named after Strontian, Scotland]
French: strontium
English: strontium
Italian: stronzio
Spanish: estroncio
Description: Strontium is a silvery-white, relatively soft metal that is obtained by heating strontium oxide (SrO) with alukinium metal. The bulk metal is portected by an oxide film, but it will burn in air if ignited, and is attacked by water. Strontium is used in special glass for televisions and VDUs, and the red colour of foreworks and flars is produced by strontium salts.
Further Materials properties
| Crystal structure: |
(cell dimensions/pm), space group,
α-Sr f.c.c. (a=608.49) Fm3m
β-Sr h.c.p. (a=432, c=706), P63/mmc
γ-Sr b.c.c. (a=485), Im3m
T (α -> β) = 506 K, T (β -> γ) = 813 K
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| X-ray diffractions mass absorption coefficients: |
CuKa 125 (µ/r) / cm2g-1
MoKa 95.0 (µ/r) / cm2g-1 |
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| Neutron scattering length: |
0.702 b/10-12 cm |
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| Thermal neutron capture cross-section: |
1.28 sa / barns |
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| Density: |
2540 kg/m-3 [293 K]; 2375 [liquid at m.p.] |
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| Melting point: |
768.85°C / 1042°K |
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| Boiling point: |
1383.85°C / 1657°K |
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| Molar volume: |
34.50 cm3 |
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| Thermal conductivity: |
35.3 [300 K] W m-1K-1 |
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| Coefficient of linear thermal expansion: |
23 x 10-6 K-1 |
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| Electrical resistivity: |
23.0 x 10-8 [295 K] Ωm |
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| Mass magnetic susceptibility: |
+1.32 x 10-8(s) kg-1m3 |
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| Radi: |
Sr2+ 127; atomic 215 (α-form); covalent 192 |
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| Electronegativity: |
0.95 (Pauling); 0.99 (Allred); 2.0 eV (absolute) |
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| Effective nuclear charge: |
2.85 (Slater); 6.07 (Clementi); 8.09 (Froese-Fischer) |
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| Number of Isotopes (incl. nuclear isomers): |
23 |
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| Isotope mass range: |
79 -> 98 |
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Biological data
| Biological role: |
None. |
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| Toxicity |
|
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| Toxic intake: |
not regarded as toxic |
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| Lethal intake: |
LD50 (chloride, oral, rat) = 2250 mg Kg-1 |
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| Hazards: |
Strontium resembles calcium in metabolism and behaviour and is absorbed by the body and stored in the skeleton. This also happens with radioactive 90Sr. which was produced by above-ground nuclear explosions in the 1950s and is widely disseminated in the environment. |
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| Level in humans |
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| Blood: |
0.031 mg dm-3 |
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| Bone: |
36 - 140 ppm |
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| Liver: |
0.05 - 0.36 ppm |
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| Muscle: |
0.12 - 0.35 ppm |
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| Daily dietary intake: |
0.8 - 5 mg |
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Total mass of element in average
[70 kg] person: |
320 mg |
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Geological data
| Minerals: | |
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| Mineral | Formula | Density | Hardness | Crystal apperance |
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| Clestite* |
SrSO4 |
3.97 |
3 - 3.5 |
orth., vit./ colourless-pale blue |
| Strontianite |
SrCO3 |
3.76 |
3.5 |
orth., vit./ resinous colourless |
| Chief ores: |
celestite, strontianite |
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| World production: |
137 000 (strontium ores) tonnes/year |
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| Producing areas: |
UK, Tunisia, Russia, Germany, Mexico, USA |
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| Reserves: |
n.a. |
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| Specimen: |
available as granules and pieces. Warning! |
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| Abundances |
|
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| Sun: |
790 (relative to H = 1 x 1012) |
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| Earth's crust: |
370 ppm |
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| Seawater |
|
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| Atlantic surface: |
7.6 ppm |
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| Atlantic deep: |
7.7 ppm |
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| Pacific surface: |
7.6 ppm |
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| Pacific deep: |
7.7 ppm |
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| Residence time: |
4 x 106 years |
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| Classification: |
recycled |
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| Oxidation state: |
II |
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Source: Emsley, J. (1998) The Elements (3rd Edition)
Other sizes and specifications on request
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