| Sulfur - S
CAS: 7704-34-9 Description: Solid, pale yellow, non-metallic Classification: Non-metal Date of Discovery: Known to the ancients Discoverer: Unknown Name Origin: Sanskrit, sulvere; Latin, sulphurium British Spelling: Sulphur |
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Atomic Number: 16
Number of Neutrons: 16 Atomic Mass: 32.066(6) amu Melting Point: 115.21 °C Boiling Point: 444.60 °C Density (293 K): 2.07 g/cm3 (orthorhombic) 1.957 g/cm3 (monoclinic) Atomic volume: 15.5 cm3/mol Electrical resistivity: 0.5e-23 10-6/cm 
Thermal conductivity: 0.00269 W/cmK Enthalpy of atomization: 278.65 kJ/mol Enthalpy of vaporization: 9.62 kJ/mol Enthalpy of fusion: 1.7175 kJ/mol Specific heat capacity: 0.71 J/gK |
Energy levels: 2-8-6
Electron configuration: [Ne]3s23p4 Crystal Structure: Orthorhombic / Monoclinic Atomic radius: 1.09 Å Covalent radius: 1.02 Å Oxidation States: -2, +2, +4, +6 Electronegativity, Pauling: 2.58 Electron affinity: 2.077104 eV First ionization energy: 10.360 eV 2nd ionization energy: 19.131 eV 3rd ionization energy: 34.83 eV Polarizability: 2.90 10-24cm3 |
| Isotope | Natural Abundance | Atomic Mass | Half-life | Decay Mode | Spin |
| 27S | 27.0188 | 21 ms |  +, 2p |
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| 29S | 28.99661 | 0.188 s | +; +, p |
5/2+ | |
| 30S | 29.984903 | 1.18 s | + |
0+ | |
| 31S | 30.979555 | 2.56 s | + |
1/2+ | |
| 32S | 95.02(9) | 31.9720707 | Stable | 0+ | |
| 33S | 0.75(1) | 32.9714585 | Stable | 3/2+ | |
| 34S | 4.21(8) | 33.9678669 | Stable | 0+ | |
| 35S | 34.9690322 | 87.2 d | - |
3/2+ | |
| 36S | 0.02(1) | 35.9670809 | Stable | 0+ | |
| 37S | 36.9711257 | 5.05 m | - |
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| 38S | 37.97116 | 2.84 h | - |
0+ | |
| 39S | 38.97514 | 11.5 s | - |
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| 40S | 39.9755 | 9 s | - |
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| 41S | 40.9800 | ||||
| 42S | 41.9815 | ||||
| 43S | 42.987 | ||||
| 44S | 43.988 | 0.12 s | -, n |
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Known to the ancients; referred to in Genesis as brimstone. Sulfur is found in
meteorites. A dark area near the crater Aristarchus on the moon has been studied by R. W. Wood with ultraviolet light. This study suggests strongly that it is a sulfur deposit. Sulfur occurs native in the vicinity of volcanoes and hot springs. It is widely distributed in nature as iron pyrites, galena, sphalerite, cinnabar, stibnite, gypsum,
Epsom salts, celestite, barite, etc. Sulfur is commercially recovered from wells sunk into the salt domes along the Gulf Coast of the U.S. It is obtained from these wells by the Frasch process, which forces heated water into the wells to melt the sulfur, which is then brought to the surface. Sulfur also occurs in natural gas and petroleum crudes and must be removed from these products. Formerly this was done chemically, which wasted the sulfur. New processes now permit recovery, and these sources promise to be very important. Large amounts of sulfur are being recovered from Alberta gas fields. Sulfur
is a pale yellow, odorless, brittle solid, which is insoluble in water but soluble in carbon disulfide. In every state, whether gas, liquid or solid, elemental sulfur occurs in more than one allotropic form or modification; these present a confusing multitude of forms whose relations are not yet fully understood. Amorphous or "plastic" sulfur is obtained by fast cooling of the crystalline form. X-ray studies indicate that amorphous sulfur may have a helical structure with eight atoms per spiral. Crystalline sulfur seems to be made of rings, each containing eight sulfur atoms, which fit together to give a normal X-ray pattern. Seventeen isotopes of sulfur are now recognized. Four occur in natural sulfur, none of which is radioactive. A finely divided form of sulfur, known as flowers of sulfur, is obtained by sublimation. Sulfur readily forms sulfides with many elements. Sulfur is a component of black gunpowder, and is used in the vulcanization of
natural rubber and a fungicide. It is also used extensively is making phosphatic fertilizers. A tremendous tonnage is used to produce sulfuric acid, the most important manufactured chemical. It is used in making sulfite paper and other papers, as a fumigant, and in the bleaching of dried fruits. The element is a good electrical insulator. Organic compounds containing sulfur are very important. Calcium sulfate, ammonium sulfate, carbon disulfide, sulfur dioxide, and hydrogen sulfide are but a few of the many other important compounds of sulfur. Sulfur is essential to life. It is a minor
constituent of fats, body fluids, and skeletal minerals. Carbon disulfide, hydrogen sulfide, and sulfur dioxide should be handled carefully. Hydrogen sulfide in small concentrations can be metabolized, but in higher concentrations it quickly can cause death by respiratory paralysis. It is insidious in that it quickly deadens the sense of smell. Sulfur dioxide is a dangerous component in atmospheric air pollution. In 1975, University of Pennsylvania scientists reported synthesis of polymeric sulfur nitride, which has the properties of a metal, although it contains no metal atoms. The material has unusual optical and electrical properties.
LINKS: The Lithium/Sulfur Dioxide Battery Recovering Hydrogen and Sulfur from Refinery Wastes Sulfur Biogeochemistry The Sulfur Lamp Sulfur Lamps--The Next Generation of Efficient Light? Sulfur Polymer Return
Sources for the information on this website include: Lide, David R., ed. CRC Handbook of Chemistry and Physics, 78th Ed., 1997-1998. |
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