|
|
| Atomic symbol: Sr |
| Atomic number: 38 |
| Atomic weight: 87.62 |
| Atomic volume: 33.7 cm3/mol |
| Density: 2.6 g/cm3 |
| Period Number: 5 |
| Group number: 2 |
| Group name: Alkali Earth |
| Element classification: Metal |
| Phase at room temperature: Solid |
| Melting Point: 1042.2 K |
| Boiling point: 1654 K |
| Heat of fusion: 8.30 kJ/mol |
| Heat of vaporization: 144.0 kJ/mol |
| Ionization Energy: 5.695 eV |
| 1st ionization energy: 549.5 kJ/mole |
| 2nd ionization energy: 1064.2 kJ/mole |
| 3rd ionization energy: 4206.7 kJ/mole |
| Electronegativity: 0.95 |
| Electron affinity: kJ/mole |
| Specific heat: 0.30 J/gK |
| Heat atomization: 164 kJ/mole atoms |
| Shells: 2,8,18,8,2 |
| Electron Shell Configuration: [Kr] 5s2 |
| Minimum oxidation number: 0 |
| Maximum oxidation number: 2 |
| Minimum common oxidation number: 0 |
| Maximum common oxidation no: 2 |
Appearance & Characteristics |
| Structure:: hcp: hexagonal close pkd |
| Color: silvery |
| Hardness: 1.8 mohs |
| Toxicity: ? |
| Characteristics: tarnishes |
| Uses: fireworks (red flame) |
| Reaction with air: vigorous, =>SrO, Sr2N3 |
| Reaction with 6M HCl: vigorous, =>H2, SrCl2 |
| Reaction with 15M HNO3: vigorous, =>Sr(NO3)2, H2 |
| Reaction with 6M NaOH: none |
| Number of isotopes: 4 |
| Oxide(s): SrO |
| Hydride(s): SrH2 |
| Chloride(s): SrCl2 |
| Atomic Radius: 215 pm |
| Ionic radius (1- ion): pm |
| Ionic radius (1+ ion): pm |
| Ionic radius (2- ion): pm |
| Ionic radius (2+ ion): 132 pm |
| Ionic radius (3+ ion): pm |
| Thermal conductivity: 35.4 J/m-sec-deg |
| Electrical conductivity: 43.478 1/mohm-cm |
| Polarizability: 27.6 A^3 |
| Source: Celestite (sulfide) |
| Relative abundance solar system: 1.371 log |
| Abundance earth's crust: 2.6 log |
| Estimated crustal abundance: 3.70×102 milligrams per kilogram |
| Estimated oceanic abundance: 7.9 milligrams per liter |
|
|
|
| (Named after Strontian, a town in Scotland.) Isolated by Davey by electrolysis in 1808, however, Adair Crawford recognized a new mineral (strontianite) as differing from other barium minerals in 1790 . |
| Strontium is softer than calcium and decomposes in water more vigorously. It does not absorb nitrogen below 3800C. It should be kept under kerosene to prevent oxidation. Freshly cut strontium has a silvery appearance, but rapidly turns a yellowish color with the formation of the oxide. The finely divided metal ignites spontaneously in air. Volatile strontium salts impart a beautiful crimson color to flames, and these salts are used in pyrotechnics and in the production of flares. Natural strontium is a mixture of four stable isotopes. |
| The major use for strontium at present is in producing glass for color television picture tubes. It has also found use in producing ferrite magnets and in refining zinc. Strontium titanate is an interesting optical material as it has an extremely high refractive index and an optical dispersion greater than that of diamond. It has been used as a gemstone, but is very soft. It does not occur naturally. |
| Strontium is found chiefly as celestite and strontianite. The metal can be prepared by electrolysis of the fused chloride mixed with potassium chloride, or is made by reducing strontium oxide with aluminum in a vacuum at a temperature at which strontium distills off. Three allotropic forms of the metal exist, with transition points at 235 and 5400C. |
| Sixteen other unstable isotopes are known to exist. Of greatest importance is 90Sr with a half-life of 29 years. It is a product of nuclear fallout and presents a health problem. This isotope is one of the best long-lived high-energy beta emitters known, and is used in SNAP (Systems for Nuclear Auxilliary Power) devices. These devices hold promise for use in space vehicles, remote weather stations, navigational buoys, etc., and where a lightweight, long-lived, nuclear-electric power source is needed. |
 |
Would you like to contact senior executives directly? Join our network on OurMetals.com
It's free and only takes 2 minutes to register. |
|
|
|
 Company
|
| SEKOM Handelsges.m.b.H.... |
|
Our company is a private firm founded in 1990 with aim to develop export and import with Russia. We do promote EU industrial and consumer goods in Russia and strongly support marketing of Russian and CIS industrial products and services.
|
|
0 selling
&
0 buying
leads |
|
Friendly links
|
|
