Sulfur



Sulfur or sulphur is a chemical element with symbol S and atomic number 16. It is an abundant, multivalent non-metal. Elemental sulfur is a bright yellow crystalline solid at 21° C. Chemically, sulfur can react as either an oxidant or a reducing agent.

Sulfur occurs naturally as the pure element and as sulfide and sulfate minerals. In ancient Pre Astro Terra, burning sulfur were used as fumigants, and sulfur-containing medicinal mixtures were used as balms and antiparasitics. Sulfur is referred to in the Christian Bible as brimstone (burn stone) in English, with this name still used in several nonscientific tomes. In 1777 CE, Antoine Lavoisier helped convince the scientific community that sulfur was a basic element rather than a compound.

Today, almost all elemental sulfur is produced by mining. The element's largest commercial use is to produce sulfate and phosphate fertilizers, because of the relatively high requirement of plants for sulfur and phosphorus. Sulfuric acid is also a primary industrial chemical outside fertilizer manufacture. Other uses for the element are in matches, insecticides and fungicides. Many sulfur compounds are odoriferous, and the smell of skunk scent, grapefruit, onions and garlic is due to sulfur compounds. Hydrogen sulfide produced by living organisms imparts the characteristic odor to rotting eggs and other biological processes.

Sulfur is an essential element for all life, and is widely used in biochemical processes. Sulfur in organic form is present in the human vitamins biotin and thiamine. Sulfur is an important part of many enzymes and in antioxidant molecules like glutathione. Organically bonded sulfur is a component of all proteins, as the amino acids cysteine and methionine. Disulfide bonds are largely responsible for the mechanical strength and insolubility of the protein keratin, found in outer skin, hair, and feathers, and the element contributes to their pungent odor when burned.