Sulfur is a chemical element with the atomic number 16 denoted by the symbol S. It is a naturally abundant, multivalent nonmetal. In its native form, at room temperature and pressure, sulfur is a soft bright yellow crystalline solid. In nature, it can be found as the pure element and in the form of sulfide and sulfate minerals. It is found in two of the coded protein amino acids: cysteine and methionine.
The strong smell of sulfur is usually due to the presence of hydrogen sulfide (H2S) or organosulfur compounds. Elemental sulfur is fairly insoluble in water. Common oxidation states of sulfur include −2, +2, +4, and +6. Sulfur forms stable compounds with most elements. Sulfur forms more than 30 solid allotropes, more than any other element. Besides S8, several other rings are known. Elemental sulfur is an equilibrium mixture of S8, S7, and small amounts of S6.
Sulfur is unusual in that its viscosity in its molten state, unlike most other liquids,...