white phosphorus

White phosphorus, yellow phosphorus, or simply tetraphosphorus (P4) is an allotrope of phosphorus. It is a translucent waxy solid that quickly yellows in light (due to its photochemical conversion into red phosphorus), for this reason, impure white phosphorus is called yellow phosphorus. White phosphorus is the first allotrope of phosphorus that was discovered, isolated for the first time in 1669 by Henning Brand.

When in an oxygen-containing atmosphere, it will exhibit a faint green glow in the absence of light. White phosphorus is also highly flammable and pyrophoric (self-igniting at standard temperature and pressure) upon contact with air. It is toxic, causing severe liver damage upon ingestion and phossy jaw from chronic ingestion or inhalation. The combustion of this form has a characteristic garlic odor, and samples are commonly coated with white "diphosphorus pentoxide", which consists of P4O10 tetrahedra with oxygen inserted between the phosphorus atoms and at their vertices. White phosphorus is only slightly soluble in water and can be stored under water. P4 is soluble in benzene, oils, carbon disulfide, and disulfur dichloride.