Phosphorus

Phosphorus is a chemical element, with atomic number Z = 15, that is present in all living organisms in the form of organophosphates and as calcium phosphates such as hydroxyapetite (Ca₁₀(PO₄)₆(OH)₂) and fluoroapatite (Ca₁₀(PO₄)₆F₂) found in teeth and bones. Many cell signaling cascades in living organisms operate by a series of phosphorylation events in which a phosphate group (PO₄)^2- is either added to a protein by a kinase or removed from a protein by a phosphorylase. Unlike other elements in group VA, phosphorus is never found as a pure element in nature, but only in combination with other elements. Both red phosphorus and tetraphosphorus trisulfide are used in common matches because they are easily ignited by heat. However, the agricultural industry is the largest user of phosphorus in the form of fertilizers.

production of elemental phosphorus

Calcium phosphate (phosphate rock), mostly mined in Florida and North Africa, can be heated to 1200-1500 Celcius with sand, which is mostly SiO₂, and coke (impure carbon) to produce vaporized tetraphosphorus, P₄, (mp. 44.2 C) which is subsequently condenced into a white power under water to prevent oxidation. Even under water, white phosphorus is slowly converted to the more stable red phosphorus allotrope (mp. 597C). Both the white and red allotropes of phosphoruus are insoluble in water.