Sulfur
. Sulfur, symbol S, tasteless, odorless, light yellow nonmetallic element. Sulfur is in group 16 (or VIa) of the periodic table . Its atomic number is 16, and its atomic weight is 32.064. Also called brimstone, sulfur has been known since prehistoric times and is mentioned in the Bible and classical records. Because of its flammability, alchemists regarded sulfur as essential in combustion (see Alchemy). All forms of sulfur are insoluble in water, but the crystalline forms are soluble in carbon disulfide. When ordinary sulfur melts, it forms a straw-colored liquid that turns darker with additional heating and then finally boils. When molten sulfur is slowly cooled, its physical properties change in accordance with the temperature, pressure, and method of crust formation. Sulfur ranks 16th in abundance among the elements in the earth's crust and is found widely distributed in both the free and combined states. In combination it occurs in many important metallic sulfides, such as lea...