Sulfur is a versatile element and is used in the pharmaceutical, medical, and industrial industries to make fertilizers, create batteries and produce goods like rubbers and insecticides. Sulfur is pale yellow in color; it is also odorless and brittle in its solid form. Sulfur comes in three allotropic forms: orthorhombic, monoclinic and amorphous, and depending on its form, it varies in physical properties and suitability for various purposes.
Sulfur is the 10th most abundant element in the universe, and it was used by ancient Greeks (as it still is today) for making insecticides — Homer briefly mentioned this use. Although sometimes used in its natural and purest form, most sulfur is processed to become sulfuric acid. In this acidic form, it is added to fertilizers, used in lead-acid batteries, and used to facilitate many industrial processes, including packaging and processing. Historically, sulfur was commonly added to gunpowder as a fuel, although sulfur-free compounds are now available. It was also used to create numerous dyes. In its gaseous form, sulfur is used as a bleaching agent, solvent and disinfectant. Sulfur is lightweight and resists degradation in the atmosphere: it, along with water, creates acid rain, essentially a weak solution of sulfurous acid.