SULFUR

[32.059,32.076]32.06±0.02(abridged) 1st: 999.6 kJ/mol2nd: 2252 kJ/mol3rd: 3357 kJ/mol(more) ve viewtalkedit Sulfur(American spellingand thepreferred IUPAC name) orsulphur(Commonwealth spelling)is achemical element; it hassymbolSandatomic number16.​‍​​​​​‍​‍‍‍‍​‍‍ It isabundant,multivalentandnonmetallic. Undernormal conditions, sulfur atoms formcyclic octatomic moleculeswith the chemical formulaS8. Elemental sulfur is a bright yellow,crystallinesolid atroom temperature. Sulfur is the tenth most abundant element by mass in the universe and the fifth most common onEarth. Though sometimes found in pure,nativeform, sulfur on Earth usually occurs assulfideandsulfate minerals. Being abundant in native form, sulfur was known in ancient times, being mentioned for its uses inancient India,ancient Greece,China, andancient Egypt. Historically and in literature sulfur is also calledbrimstone,which means "burning stone".Almost all elemental sulfur is produced as a byproduct of removing sulfur-containing contaminants fromnatural gasandpetroleum.The greatest commercial use of the element is the production ofsulfuric acidfor sulfate and phosphatefertilizers, and other chemical processes. Sulfur is used inmatches,insecticides, andfungicides. Many sulfur compounds are odoriferous, and the smells of odorized natural gas,skunkscent,bad breath,grapefruit, andgarlicare due toorganosulfurcompounds.Hydrogen sulfidegives the characteristic odor to rotting eggs and other biological processes. Sulfur is anessential elementfor all life, almost always in the form oforganosulfur compoundsormetal sulfides.Amino acids(twoproteinogenic:cysteineandmethionine, and many othernon-coded:cystine,taurine, etc.) and two vitamins (biotinandthiamine) are organosulfur compounds crucial for life. Manycofactorsalso contain sulfur, includingglutathione, andiron–sulfur proteins.Disulfides, S–S bonds, confer mechanical strength and insolubility of the (among others) proteinkeratin, found in outer skin, hair, and feathers. Sulfur is one of the core chemical elements needed forbiochemicalfunctioning and is an elementalmacronutrientfor all living organisms.