Sulfur is a chemical element characterized by the symbol S and atomic number 16. It is classified as an abundant, multivalent, and nonmetallic substance. Under normal conditions, sulfur atoms arrange themselves into cyclic octatomic molecules with the chemical formula S8.
At room temperature, elemental sulfur exists as a bright yellow, crystalline solid. While it is a fundamental component of many chemical processes, its primary physical identity is defined by these distinct crystalline properties and its molecular structure.