Is the chemical element with atomic number 16, represented by the symbol S. It is an abundant, multivalentnon-metal. At normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow crystalline solid. Chemically, sulfur can react as either an oxidant or reducing agent. It oxidizes most metals and several nonmetals, including carbon, which leads to its negatives charge in most organosulfur compounds, but it reduces several strong oxidants, such as oxygen and fluorine.