Sulfur(orsulphurinBritish English) is achemical elementwith thesymbolSandatomic number16. It isabundant,multivalentandnonmetallic. Undernormal conditions, sulfur atoms form cyclic octatomic molecules with a 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 on Earth.