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Phosphorus (P)

a non-metallic element that all animals and plants need for normal growth


atomic number 15
atomic mass 30.97376 amu

melting point 44.15 C (111.47 F)
boiling point 280.5 C (536.9 F)

isotopes 6

There are three main allotropes (types) of phosphorus, white, red, and black. White phosphorus is a soft, waxy solid made from one of the phosphorus minerals by various methods. It combines readily with other elements and ignites in air at room temperature, so is usually stored and shipped under water. It glows when exposed to air, hence the name phosphorus. White phosphorus is very poisonous. Red phosphorus is a brownish-red powder prepared by heating white phosphorus to 250 C, or by exposing it to sunlight. It does not burn as readily as white, nor is it poisonous or phosphorescent. Black (violet) phosphorus resembles graphite and is prepared by heating white phosphorus under high pressure.

white, red (granular and solid), and black phosphorus
white, red (granular and solid), and black phosphorus


Phosphorus is not found free in nature, but there are a number of phosphate-bearing minerals, with the most common being apatite and hydroxypatite. The usual production method involves heating a phosphate with sand and carbon in an electric furnace; it is a very energy intensive process.


Phosphorus is a major component of many fertilizers and detergents, and phosphoric compounds are used in the production of steel, china, and baking powder. Because of its phosphorescent qualities, red phosphorus is used in safety matches, fireworks, smoke bombs and pesticides.


Phosphorus was discovered by Hennig Brand in 1669 by boiling, filtering and otherwise processing as many as 60 buckets of urine. Its name is from the Greek words phs (light) and phoros (bearer).

Hennig Brand praying after his discovery of phosphorus, aspainted by Joseph Wright in 1771
Hennig Brand

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This page was last updated on 09/03/2018.