AskDefine | Define phosphorus

Dictionary Definition



1 a multivalent nonmetallic element of the nitrogen family that occurs commonly in inorganic phosphate rocks and as organic phosphates in all living cells; is highly reactive and occurs in several allotropic forms [syn: P, atomic number 15]
2 a planet (usually Venus) seen just before sunrise in the eastern sky [syn: morning star, daystar]

User Contributed Dictionary

see Phosphorus



  • (RP): fŏsʹfərəs, /ˈfɒsfərəs/, /"fQsf@r@s/
  • (US): fäsʹfərəs, /ˈfɑsfɚəs/, /"fAsf@`@s/


From Latinised Greek |phosphorus, from φωσφόρος, from φῶς + φέρω.



  1. a chemical element (symbol P) with an atomic number of 15, that exists in several allotropic forms.
  2. any substance exhibiting phosphorescence; a phosphor

Usage notes

  • Do not confuse phosphorus with phosphorous, which is an adjective.

Derived terms

Related terms


See also

External links

For etymology and more information refer to: (A lot of the translations were taken from that site with permission from the author)




Extensive Definition

see Phosphorus (morning star) for the Greek name of the morning star.
Phosphorus, (), is the chemical element that has the symbol P and atomic number 15. The name comes from the (meaning "light") and φόρος (meaning "bearer"). A multivalent nonmetal of the nitrogen group, phosphorus is commonly found in inorganic phosphate rocks.
Due to its high reactivity, phosphorus is never found as a free element in nature on Earth. One form of phosphorus (white phosphorus) emits a faint glow upon exposure to oxygen — hence its Greek derivation, Φωσφόρος meaning "light-bearer" (Latin Lucifer), the planet Venus as "Morning Star".
Phosphorus is a component of DNA and RNA and an essential element for all living cells. The most important commercial use of phosphorus-based chemicals is the production of fertilizers.
Phosphorus compounds are also widely used in explosives, nerve agents, friction matches, fireworks, pesticides, toothpaste, and detergents.



Phosphorus is an excellent example of an element that exhibits allotropy, as its various allotropes have strikingly different properties.
The two most common allotropes are white phosphorus and red phosphorus. A third form, scarlet phosphorus, is obtained by allowing a solution of white phosphorus in carbon disulfide to evaporate in sunlight. A fourth allotrope, black phosphorus, is obtained by heating white phosphorus under very high pressures (12,000 atmospheres). In appearance, properties and structure it is very like graphite, being black and flaky, a conductor of electricity and has puckered sheets of linked atoms. Another allotrope is diphosphorus - which is highly reactive.
White phosphorus () exists as individual molecules made up of four atoms in a tetrahedral arrangement, resulting in very high ring strain and instability. It contains 6 single bonds.
White phosphorus is a white, waxy transparent solid. This allotrope is thermodynamically unstable at normal condition and will gradually change to red phosphorus. This transformation, which is accelerated by light and heat, makes white phosphorus almost always contain some red phosphorus and appear yellow. For this reason, it is also called yellow phosphorus. It glows greenish in the dark (when exposed to oxygen), is highly flammable and pyrophoric (self-igniting) upon contact with air as well as toxic (causing severe liver damage on ingestion). The infamous incendiary bomb Napalm relies, among others, on this principle to spontaneously ignite. The odour of combustion of this form has a characteristic garlic smell, and samples are commonly coated with white "(di)phosphorus pentoxide", which consists of P4O10 tetrahedra with oxygen inserted between the phosphorus atoms and at their vertices. White phosphorus is insoluble in water but soluble in carbon disulfide. The white allotrope can be produced using several different methods. In one process, calcium phosphate, which is derived from phosphate rock, is heated in an electric or fuel-fired furnace in the presence of carbon and silica
Black phosphorus has an orthorhombic structure (Cmca) and is the least reactive allotrope. It consists of many six-membered rings which are interlinked. Each atom is bonded to three other atoms. A recent synthesis of black phosphorus using metal salts as catalysts has been reported.
The diphosphorus allotrope (P2) can be obtained normally only under extreme conditions (for example, from P4 at 1100 kelvin). Nevertheless, some advancements were obtained in generating the diatomic molecule in homogeneous solution, under normal conditions with the use by some transitional metal complexes (based on, for example, tungsten and niobium).


The glow from phosphorus was the attraction of its discovery around 1669, but the mechanism for that glow was not fully described until 1974. It was known from early times that the glow would persist for a time in a stoppered jar but then cease. Robert Boyle in the 1680s ascribed it to "debilitation" of the air; in fact, it is oxygen being consumed. By the 18th century, it was known that in pure oxygen phosphorus does not glow at all; there is only a range of partial pressure at which it does. Heat can be applied to drive the reaction at higher pressures.
In 1974, the glow was explained by R. J. van Zee and A. U. Khan.
  • 33P; a beta-emitter (0.25 MeV) with a half-life of 25.4 days. It is used in life-science laboratories in applications in which lower energy beta emissions are advantageous such as DNA sequencing.


See also Phosphate minerals.
Due to its reactivity with air and many other oxygen-containing substances, phosphorus is not found free in nature but it is widely distributed in many different minerals.
Phosphate rock, which is partially made of apatite (an impure tri-calcium phosphate mineral), is an important commercial source of this element. About 50 per cent of the global phosphorus reserves are in the Arab nations. Large deposits of apatite are located in China, Russia, Morocco, Florida, Idaho, Tennessee, Utah, and elsewhere. Albright and Wilson in the United Kingdom and their Niagara Falls plant, for instance, were using phosphate rock in the 1890s and 1900s from Connetable, Tennessee and Florida; by 1950 they were using phosphate rock mainly from Tennessee and North Africa
At today's rate of consumption, the supply of phosphorus is estimated to run out in 345 years.


See also Phosphorus compounds

As an exception to the octet rule

The simple Lewis structure for the trigonal bipyramidal PCl5 molecule contains five covalent bonds, implying a hypervalent molecule with ten valence electrons contrary to the octet rule.
An alternate description of the bonding, however, respects the octet rule by using 3-center-4-electron (3c-4e) bonds. In this model the octet on the P atom corresponds to six electrons which form three Lewis (2c-2e) bonds to the three equatorial Cl atoms, plus the two electrons in the 3-centre Cl-P-Cl bonding molecular orbital for the two axial Cl electrons. The two electrons in the corresponding nonbonding molecular orbital are not included because this orbital is localized on the two Cl atoms and does not contribute to the electron density on P.
However, it should always be remembered that the octet rule is a not some universal rule of chemical bonding, and while many compounds obey it, there are many elements (the majority, in fact) to which it just does not apply.


Spelling and etymology

According to the Oxford English Dictionary the correct spelling of the element is phosphorus. The word phosphorous is the adjectival form of the P3+ valency: so, just as sulfur forms sulfurous and sulfuric compounds, phosphorus forms phosphorous compounds (see e.g. phosphorous acid) and P5+ valency phosphoric compounds (see e.g. Phosphoric acids and phosphates).


Organic compounds of phosphorus form a wide class of materials, some of which are extremely toxic. Fluorophosphate esters are among the most potent neurotoxins known. A wide range of organophosphorus compounds are used for their toxicity to certain organisms as pesticides (herbicides, insecticides, fungicides, etc.) and weaponized as nerve agents. Most inorganic phosphates are relatively nontoxic and essential nutrients. For environmentally adverse effects of phosphates see eutrophication and algal blooms.
The white phosphorus allotrope should be kept under water at all times as it presents a significant fire hazard due to its extreme reactivity with atmospheric oxygen, and it should only be manipulated with forceps since contact with skin can cause severe burns. Chronic white phosphorus poisoning leads to necrosis of the jaw called "phossy jaw". Ingestion of white phosphorus may cause a medical condition known as "Smoking Stool Syndrome".
When the white form is exposed to sunlight or when it is heated in its own vapour to 250°C, it is transmuted to the red form, which does not phosphoresce in air. The red allotrope does not spontaneously ignite in air and is not as dangerous as the white form. Nevertheless, it should be handled with care because it reverts to white phosphorus in some temperature ranges and it also emits highly toxic fumes that consist of phosphorus oxides when it is heated.
Upon exposure to elemental phosphorus, in the past it was suggested to wash the affected area with 2% copper sulfate solution to form harmless compounds that can be washed away. According to the recent US Navy's Treatment of Chemical Agent Casualties and Conventional Military Chemical Injuries: FM8-285: Part 2 Conventional Military Chemical Injuries, "Cupric (copper(II)) sulfate has been used by U.S. personnel in the past and is still being used by some nations. However, copper sulfate is toxic and its use will be discontinued. Copper sulfate may produce kidney and cerebral toxicity as well as intravascular hemolysis."
The manual suggests instead "a bicarbonate solution to neutralize phosphoric acid, which will then allow removal of visible WP. Particles often can be located by their emission of smoke when air strikes them, or by their phosphorescence in the dark. In dark surroundings, fragments are seen as luminescent spots." Then, "Promptly debride the burn if the patient's condition will permit removal of bits of WP which might be absorbed later and possibly produce systemic poisoning. DO NOT apply oily-based ointments until it is certain that all WP has been removed. Following complete removal of the particles, treat the lesions as thermal burns." As white phosphorus readily mixes with oils, any oily substances or ointments are not recommended until the area is thoroughly cleaned and all white phosphorus removed.
Further warnings of toxic effects and recommendations for treatment can be found in the Emergency War Surgery NATO Handbook: Part I: Types of Wounds and Injuries: Chapter III: Burn Injury: Chemical Burns And White Phosphorus injury.

DEA List I status

Phosphorus can reduce elemental iodine to hydroiodic acid, which is a reagent effective for reducing ephedrine or pseudoephedrine to methamphetamine. For this reason, two allotropes of elemental phosphorus—red phosphorus and white phosphorus—were designated by the United States Drug Enforcement Administration as List I precursor chemicals under 21 CFR 1310.02 effective November 17, 2001. As a result, in the United States, handlers of red phosphorus or white phosphorus are subject to stringent regulatory controls pursuant to the Controlled Substances Act in order to reduce diversion of these substances for use in clandestine production of controlled substances.


External links

phosphorus in Afrikaans: Fosfor
phosphorus in Arabic: فسفور
phosphorus in Asturian: Fósforu
phosphorus in Azerbaijani: Fosfor
phosphorus in Belarusian: Фосфар
phosphorus in Bulgarian: Фосфор
phosphorus in Bengali: ফসফরাস
phosphorus in Bosnian: Fosfor
phosphorus in Catalan: Fòsfor
phosphorus in Corsican: Fosfaru
phosphorus in Czech: Fosfor
phosphorus in Welsh: Ffosfforws
phosphorus in Danish: Fosfor
phosphorus in German: Phosphor
phosphorus in Dhivehi: ފޮސްފަރަސް
phosphorus in Modern Greek (1453-): Φωσφόρος
phosphorus in Esperanto: Fosforo
phosphorus in Spanish: Fósforo
phosphorus in Estonian: Fosfor
phosphorus in Basque: Fosforo
phosphorus in Persian: فسفر
phosphorus in Finnish: Fosfori
phosphorus in French: Phosphore
phosphorus in Friulian: Fosfar
phosphorus in Irish: Fosfar
phosphorus in Galician: Fósforo (elemento)
phosphorus in Manx: Fosfaar
phosphorus in Hebrew: זרחן
phosphorus in Hindi: फास्फोरस
phosphorus in Croatian: Fosfor
phosphorus in Haitian: Fosfò
phosphorus in Hungarian: Foszfor
phosphorus in Armenian: Ֆոսֆոր
phosphorus in Indonesian: Fosfor
phosphorus in Ido: Fosfo
phosphorus in Icelandic: Fosfór
phosphorus in Italian: Fosforo
phosphorus in Japanese: リン
phosphorus in Lojban: sackycmu
phosphorus in Korean: 인
phosphorus in Kurdish: Fosfor
phosphorus in Latin: Phosphorus
phosphorus in Luxembourgish: Phosphor
phosphorus in Lithuanian: Fosforas
phosphorus in Latvian: Fosfors
phosphorus in Maori: Pūtūtae-whetū
phosphorus in Macedonian: Фосфор
phosphorus in Malayalam: ഫോസ്ഫറസ്
phosphorus in Marathi: फॉस्फरस
phosphorus in Malay (macrolanguage): Fosforus
phosphorus in Low German: Phosphor
phosphorus in Dutch: Fosfor
phosphorus in Norwegian Nynorsk: Fosfor
phosphorus in Norwegian: Fosfor
phosphorus in Novial: Fosfore
phosphorus in Occitan (post 1500): Fosfòr
phosphorus in Polish: Fosfor
phosphorus in Portuguese: Fósforo
phosphorus in Quechua: Phusphuru
phosphorus in Romanian: Fosfor
phosphorus in Russian: Фосфор
phosphorus in Sicilian: Fosfuru
phosphorus in Serbo-Croatian: Fosfor
phosphorus in Simple English: Phosphorus
phosphorus in Slovak: Fosfor
phosphorus in Slovenian: Fosfor
phosphorus in Albanian: Fosfori
phosphorus in Serbian: Фосфор
phosphorus in Swedish: Fosfor
phosphorus in Swahili (macrolanguage): Posferi
phosphorus in Tamil: பாஸ்பரஸ்
phosphorus in Tajik: Фосфор
phosphorus in Thai: ฟอสฟอรัส
phosphorus in Turkish: Fosfor
phosphorus in Ukrainian: Фосфор
phosphorus in Urdu: فاسفورس
phosphorus in Uzbek: Fosfor
phosphorus in Vietnamese: Phốtpho
phosphorus in Chinese: 磷
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