Sulfur | ||||||||||||||||||||||||||||||||||||
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Alternative name | Sulphur (British spelling) | |||||||||||||||||||||||||||||||||||
Allotropes | see Allotropes of sulfur | |||||||||||||||||||||||||||||||||||
Appearance | Lemon yellow sintered microcrystals | |||||||||||||||||||||||||||||||||||
Standard atomic weight Ar°(S) | ||||||||||||||||||||||||||||||||||||
Sulfur in the periodic table | ||||||||||||||||||||||||||||||||||||
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Atomic number (Z) | 16 | |||||||||||||||||||||||||||||||||||
Group | group 16 (chalcogens) | |||||||||||||||||||||||||||||||||||
Period | period 3 | |||||||||||||||||||||||||||||||||||
Block | p-block | |||||||||||||||||||||||||||||||||||
Electron configuration | [Ne] 3s2 3p4 | |||||||||||||||||||||||||||||||||||
Electrons per shell | 2, 8, 6 | |||||||||||||||||||||||||||||||||||
Physical properties | ||||||||||||||||||||||||||||||||||||
Phase at STP | solid | |||||||||||||||||||||||||||||||||||
Melting point | alpha (α-S8): 388.36 K (115.21 °C, 239.38 °F) | |||||||||||||||||||||||||||||||||||
Boiling point | 717.8 K (444.6 °C, 832.3 °F) | |||||||||||||||||||||||||||||||||||
Density (near r.t.) | alpha (α-S8): 2.07 g/cm3 beta (β-S8): 1.96 g/cm3 gamma (γ-S8): 1.92 g/cm3 | |||||||||||||||||||||||||||||||||||
when liquid (at m.p.) | 1.819 g/cm3 | |||||||||||||||||||||||||||||||||||
Critical point | 1314 K, 20.7 MPa | |||||||||||||||||||||||||||||||||||
Heat of fusion | beta (β-S8): 1.727 kJ/mol | |||||||||||||||||||||||||||||||||||
Heat of vaporization | beta (β-S8): 45 kJ/mol | |||||||||||||||||||||||||||||||||||
Molar heat capacity | 22.75 J/(mol·K) | |||||||||||||||||||||||||||||||||||
Vapor pressure
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Atomic properties | ||||||||||||||||||||||||||||||||||||
Oxidation states | −2, −1, 0, +1, +2, +3, +4, +5, +6 (a strongly acidic oxide) | |||||||||||||||||||||||||||||||||||
Electronegativity | Pauling scale: 2.58 | |||||||||||||||||||||||||||||||||||
Ionization energies |
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Covalent radius | 105±3 pm | |||||||||||||||||||||||||||||||||||
Van der Waals radius | 180 pm | |||||||||||||||||||||||||||||||||||
Spectral lines of sulfur | ||||||||||||||||||||||||||||||||||||
Other properties | ||||||||||||||||||||||||||||||||||||
Natural occurrence | primordial | |||||||||||||||||||||||||||||||||||
Crystal structure | alpha (α-S8): orthorhombic (oF128) | |||||||||||||||||||||||||||||||||||
Lattice constants | a = 1.0460 nm b = 1.2861 nm c = 2.4481 nm (at 20 °C)[3] | |||||||||||||||||||||||||||||||||||
Crystal structure | beta (β-S8): monoclinic (mP48) | |||||||||||||||||||||||||||||||||||
Lattice constants | a = 1.0923 nm b = 1.0851 nm c = 1.0787 nm β = 95.905° (at 20 °C)[3] | |||||||||||||||||||||||||||||||||||
Thermal conductivity | 0.205 W/(m⋅K) (amorphous) | |||||||||||||||||||||||||||||||||||
Electrical resistivity | 2×1015 Ω⋅m (at 20 °C) (amorphous) | |||||||||||||||||||||||||||||||||||
Magnetic ordering | diamagnetic[4] | |||||||||||||||||||||||||||||||||||
Molar magnetic susceptibility | alpha (α-S8): −15.5×10−6 cm3/mol (298 K)[5] | |||||||||||||||||||||||||||||||||||
Bulk modulus | 7.7 GPa | |||||||||||||||||||||||||||||||||||
Mohs hardness | 2.0 | |||||||||||||||||||||||||||||||||||
CAS Number | 7704-34-9 | |||||||||||||||||||||||||||||||||||
History | ||||||||||||||||||||||||||||||||||||
Discovery | before 2000 BCE[6] | |||||||||||||||||||||||||||||||||||
Recognized as an element by | Antoine Lavoisier (1777) | |||||||||||||||||||||||||||||||||||
Isotopes of sulfur | ||||||||||||||||||||||||||||||||||||
34S abundances vary greatly (between 3.96 and 4.77 percent) in natural samples. | ||||||||||||||||||||||||||||||||||||
Sulfur (also spelled sulphur in British English) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with the chemical formula S8. Elemental sulfur is a bright yellow, crystalline solid at room temperature.
Sulfur is the tenth most abundant element by mass in the universe and the fifth most common on Earth. Though sometimes found in pure, native form, sulfur on Earth usually occurs as sulfide and sulfate minerals. Being abundant in native form, sulfur was known in ancient times, being mentioned for its uses in ancient India, ancient Greece, China, and ancient Egypt. Historically and in literature sulfur is also called brimstone,[7] which means "burning stone".[8] Today, almost all elemental sulfur is produced as a byproduct of removing sulfur-containing contaminants from natural gas and petroleum.[9][10] The greatest commercial use of the element is the production of sulfuric acid for sulfate and phosphate fertilizers, and other chemical processes. Sulfur is used in matches, insecticides, and fungicides. Many sulfur compounds are odoriferous, and the smells of odorized natural gas, skunk scent, bad breath, grapefruit, and garlic are due to organosulfur compounds. Hydrogen sulfide gives the characteristic odor to rotting eggs and other biological processes.
Sulfur is an essential element for all life, almost always in the form of organosulfur compounds or metal sulfides. Amino acids (two proteinogenic: cysteine and methionine, and many other non-coded: cystine, taurine, etc.) and two vitamins (biotin and thiamine) are organosulfur compounds crucial for life. Many cofactors also contain sulfur, including glutathione, and iron–sulfur proteins. Disulfides, S–S bonds, confer mechanical strength and insolubility of the (among others) protein keratin, found in outer skin, hair, and feathers. Sulfur is one of the core chemical elements needed for biochemical functioning and is an elemental macronutrient for all living organisms.
Greenwd
was invoked but never defined (see the help page).