Phosphorus

 is a metallic chemical element in the periodic table that has the symbol P and atomic number 15.

(From the Greek language phôs meaning "light", and phoros meaning "bearer"), is the chemical element in the periodic table that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus is commonly found in inorganic phosphate rocks and in all living cells. Due to its high reactivity, it is never found as a free element in nature. It emits a faint glow upon exposure to oxygen (hence its Greek derivation and the Latin meaning 'morning star'), occurs in several allotropic forms, and is an essential element for living organisms. The most important commercial use of phosphorus is in the production of fertilizers. It is also widely used in explosives, friction matches, fireworks, pesticides, toothpaste, and detergents.

Notable characteristics:Common phosphorus forms a waxy white solid that has a characteristic disagreeable smell similar to that of garlic. Pure forms of the element are colorless and transparent. This nonmetal is not soluble in water, but it is soluble in carbon disulfide. Pure phosphorus ignites spontaneously in air and burns to produce phosphorus pentoxide.

Concentrated phosphoric acids, which can consist of 70% to 75% P₂O₅ are very important to agriculture and farm production in the form of fertilizers. Global demand for fertilizers led to large increases in phosphate (PO₄^3-) production in the second half of the 20th century. Other uses;

• Phosphates are utilized in the making of special glasses that are used for sodium lamps.
• Bone-ash, calcium phosphate, is used in the production of fine china .
• Sodium tripolyphosphate made from phosphoric acid is used in laundry detergents in several countries, and banned for this use in others.
• Phosphoric acid made from elementary phosphorus is used in food applications such as soda beverages. The acid is also a starting point to make food grade phosphates. These include mono-calcium phosphate which is employed in baking powder and sodium tripolyphosphate and other sodium phosphates. Among other uses, these are used to improve the characteristics of processed meat and cheese. Others are used in toothpaste. Trisodium phosphate is used in cleaning agents to soften water and for preventing pipe/boiler tube corrosion.
• Phosphorus is widely used to make organophosphorus compounds, through the intermediates phosphorus chlorides and phosphorus sulphide. These have many applications, including in plasticizers, flame retardants, pesticides, extraction agents, and water treatment.
• This element is also an important component in steel production, in the making of phosphor bronze, and in many other related products.
• White phosphorus is used in military applications as incendiary bombs, for smoke-screening as smoke pots and smoke bombs, and in tracer ammunition.
• Red phosphorus is essential for manufacturing matchbook strikers, flares, and, most notoriously, methamphetamine.
• In trace amounts, phosphorus is used as a dopant for N-type semiconductors.
• ³²P and ³³P are used as radioactive tracers in biochemical laboratories (see #Isotopes).