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58-412: Although phosphorus ( 15 P) has 22 isotopes from P to P, only P is stable; as such, phosphorus is considered a monoisotopic element . The longest-lived radioactive isotopes are P with a half-life of 25.34 days and P with a half-life of 14.268 days. All others have half-lives of under 2.5 minutes, most under a second. The least stable known isotope is P, with a half-life of 2 milliseconds. P

116-473: A metallic form to a semimetallic form below 13.2 °C (55.8 °F). As an example of allotropes having different chemical behaviour, ozone (O 3 ) is a much stronger oxidizing agent than dioxygen (O 2 ). Typically, elements capable of variable coordination number and/or oxidation states tend to exhibit greater numbers of allotropic forms. Another contributing factor is the ability of an element to catenate . Examples of allotropes include: Among

174-483: A solid , liquid or gas ). The differences between these states of matter would not alone constitute examples of allotropy. Allotropes of chemical elements are frequently referred to as polymorphs or as phases of the element. For some elements, allotropes have different molecular formulae or different crystalline structures, as well as a difference in physical phase; for example, two allotropes of oxygen ( dioxygen , O 2 , and ozone , O 3 ) can both exist in

232-424: A conductor of electricity, and has puckered sheets of linked atoms. Another form, scarlet phosphorus, is obtained by allowing a solution of white phosphorus in carbon disulfide to evaporate in sunlight . When first isolated, it was observed that the green glow emanating from white phosphorus would persist for a time in a stoppered jar, but then cease. Robert Boyle in the 1680s ascribed it to "debilitation" of

290-426: A fertiliser in its pure form or part of being mixed with water in the form of sewage or sewage sludge . The most prevalent compounds of phosphorus are derivatives of phosphate (PO 4 ), a tetrahedral anion. Phosphate is the conjugate base of phosphoric acid, which is produced on a massive scale for use in fertilisers. Being triprotic, phosphoric acid converts stepwise to three conjugate bases: Phosphate exhibits

348-471: A source of P in routes to organophosphorus(III) compounds. For example, it is the precursor to triphenylphosphine : Treatment of phosphorus trihalides with alcohols and phenols gives phosphites, e.g. triphenylphosphite : Similar reactions occur for phosphorus oxychloride , affording triphenylphosphate : The name Phosphorus in Ancient Greece was the name for the planet Venus and is derived from

406-433: A tendency to form chains and rings containing P-O-P bonds. Many polyphosphates are known, including ATP . Polyphosphates arise by dehydration of hydrogen phosphates such as HPO 4 and H 2 PO 4 . For example, the industrially important pentasodium triphosphate (also known as sodium tripolyphosphate , STPP) is produced industrially by the megatonne by this condensation reaction : Phosphorus pentoxide (P 4 O 10 )

464-586: A transient intermediate in solution by thermolysis of organophosphorus precursor reagents. At still higher temperatures, P 2 dissociates into atomic P. Red phosphorus is polymeric in structure. It can be viewed as a derivative of P 4 wherein one P-P bond is broken, and one additional bond is formed with the neighbouring tetrahedron resulting in chains of P 21 molecules linked by van der Waals forces . Red phosphorus may be formed by heating white phosphorus to 250 °C (482 °F) or by exposing white phosphorus to sunlight. Phosphorus after this treatment

522-578: A variant of the Michaelis-Arbuzov reaction with electrophiles, instead reverting to another phosphorus(III) compound through a sulfonium intermediate. These compounds generally feature P–P bonds. Examples include catenated derivatives of phosphine and organophosphines. Compounds containing P=P double bonds have also been observed, although they are rare. Phosphides arise by reaction of metals with red phosphorus. The alkali metals (group 1) and alkaline earth metals can form ionic compounds containing

580-428: A white, waxy substance that glowed in the dark. Brand had discovered phosphorus. Specifically, Brand produced ammonium sodium hydrogen phosphate, (NH 4 )NaHPO 4 . While the quantities were essentially correct (it took about 1,100 litres [290 US gal] of urine to make about 60 g of phosphorus), it was unnecessary to allow the urine to rot first. Later scientists discovered that fresh urine yielded

638-495: Is amorphous . Upon further heating, this material crystallises. In this sense, red phosphorus is not an allotrope, but rather an intermediate phase between the white and violet phosphorus, and most of its properties have a range of values. For example, freshly prepared, bright red phosphorus is highly reactive and ignites at about 300 °C (572 °F), though it is more stable than white phosphorus, which ignites at about 30 °C (86 °F). After prolonged heating or storage,

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696-452: Is isoelectronic with SF 6 . The most important oxyhalide is phosphorus oxychloride , (POCl 3 ), which is approximately tetrahedral. Before extensive computer calculations were feasible, it was thought that bonding in phosphorus(V) compounds involved d orbitals. Computer modeling of molecular orbital theory indicates that this bonding involves only s- and p-orbitals. All four symmetrical trihalides are well known: gaseous PF 3 ,

754-442: Is a colourless gas and the molecules have trigonal bipyramidal geometry. PCl 5 is a colourless solid which has an ionic formulation of PCl 4 PCl 6 , but adopts the trigonal bipyramidal geometry when molten or in the vapour phase. PBr 5 is an unstable solid formulated as PBr 4 Br and PI 5 is not known. The pentachloride and pentafluoride are Lewis acids . With fluoride, PF 5 forms PF 6 , an anion that

812-456: Is a naturally occurring metal-rich phosphide found in meteorites. The structures of the metal-rich and phosphorus-rich phosphides can be complex. Phosphine (PH 3 ) and its organic derivatives (PR 3 ) are structural analogues of ammonia (NH 3 ), but the bond angles at phosphorus are closer to 90° for phosphine and its organic derivatives. Phosphine is an ill-smelling, toxic gas. Phosphorus has an oxidation number of −3 in phosphine. Phosphine

870-455: Is a radioactive isotope of phosphorus with relative atomic mass 31.973907 and half-life of 14.26 days. P is a radioactive isotope of phosphorus with beta particle-emitting radiocytotoxic activity. Emitted by P, beta particles directly damage cellular DNA and, by ionizing intracellular water to produce several types of cytotoxic free radicals and superoxides, indirectly damage intracellular biological macromolecules, resulting in tumor cell death. P

928-402: Is aged or otherwise impure (e.g., weapons-grade, not lab-grade WP) is also called yellow phosphorus. White phosphorus is highly flammable and pyrophoric (self-igniting) in air; it faintly glows green and blue in the dark when exposed to oxygen. The autoxidation commonly coats samples with white phosphorus pentoxide ( P 4 O 10 ): P 4 tetrahedra, but with oxygen inserted between

986-548: Is also required. Shielding requires special consideration. The high energy of the beta particles gives rise to secondary emission of X-rays via Bremsstrahlung (braking radiation) in dense shielding materials such as lead. Therefore, the radiation must be shielded with low density materials such as acrylic or other plastic, water, or (when transparency is not required), even wood. In 2013, astronomers detected phosphorus in Cassiopeia ;A , which confirmed that this element

1044-416: Is an artificial radioactive element. It is produced with a low yield by the neutron bombardment of P (stable). The P has a radioactive period of 25.3 days. It is a pure β-transmitter. P is used as an alternative to P in research in molecular biology. Indeed, its longer life time and especially its less energetic β spectrum make its manipulation simpler in the laboratory. In the medical field, P has been used in

1102-552: Is considered unstable, but is a product of crystalline phosphorus nitride decomposition at 1100 K. Similarly, H 2 PN is considered unstable, and phosphorus nitride halogens like F 2 PN, Cl 2 PN, Br 2 PN, and I 2 PN oligomerise into cyclic polyphosphazenes . For example, compounds of the formula (PNCl 2 ) n exist mainly as rings such as the trimer hexachlorophosphazene . The phosphazenes arise by treatment of phosphorus pentachloride with ammonium chloride: PCl 5 + NH 4 Cl → 1/ n (NPCl 2 ) n + 4 HCl When

1160-858: Is produced by hydrolysis of calcium phosphide , Ca 3 P 2 . Unlike ammonia, phosphine is oxidised by air. Phosphine is also far less basic than ammonia. Other phosphines are known which contain chains of up to nine phosphorus atoms and have the formula P n H n +2 . The highly flammable gas diphosphine (P 2 H 4 ) is an analogue of hydrazine . Phosphorus oxoacids are extensive, often commercially important, and sometimes structurally complicated. They all have acidic protons bound to oxygen atoms, some have nonacidic protons that are bonded directly to phosphorus and some contain phosphorus–phosphorus bonds. Although many oxoacids of phosphorus are formed, only nine are commercially important, and three of them, hypophosphorous acid , phosphorous acid , and phosphoric acid , are particularly important. The PN molecule

1218-450: Is produced in supernovae as a byproduct of supernova nucleosynthesis . The phosphorus-to- iron ratio in material from the supernova remnant could be up to 100 times higher than in the Milky Way in general. In 2020, astronomers analysed ALMA and ROSINA data from the massive star-forming region AFGL 5142, to detect phosphorus-bearing molecules and how they are carried in comets to

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1276-492: Is readily incorporated into bone and nucleic acids . For these reasons, Occupational Safety and Health Administration in the United States, and similar institutions in other developed countries require personnel working with P to wear lab coats, disposable gloves, and safety glasses or goggles to protect the eyes, and avoid working directly over open containers. Monitoring personal, clothing, and surface contamination

1334-469: Is stable and is therefore present at 100% abundance. The half-integer nuclear spin and high abundance of P make phosphorus-31 NMR spectroscopy a very useful analytical tool in studies of phosphorus-containing samples. Two radioactive isotopes of phosphorus have half-lives suitable for biological scientific experiments. These are: The high-energy beta particles from P penetrate skin and corneas and any P ingested, inhaled, or absorbed

1392-508: Is the acid anhydride of phosphoric acid, but several intermediates between the two are known. This waxy white solid reacts vigorously with water. With metal cations , phosphate forms a variety of salts. These solids are polymeric, featuring P-O-M linkages. When the metal cation has a charge of 2+ or 3+, the salts are generally insoluble, hence they exist as common minerals. Many phosphate salts are derived from hydrogen phosphate (HPO 4 ). PCl 5 and PF 5 are common compounds. PF 5

1450-416: Is the anhydride of P(OH) 3 , the minor tautomer of phosphorous acid. The structure of P 4 O 6 is like that of P 4 O 10 without the terminal oxide groups. Symmetric phosphorus(III) trithioesters (e.g. P(SMe) 3 ) can be produced from the reaction of white phosphorus and the corresponding disulfide , or phosphorus(III) halides and thiolates . Unlike the corresponding esters, they do not undergo

1508-524: Is the electrons are highly delocalized . This has been illustrated by calculations of the magnetically induced currents, which sum up to 29 nA/T, much more than in the archetypical aromatic molecule benzene (11 nA/T). White phosphorus exists in two crystalline forms: α (alpha) and β (beta). At room temperature, the α-form is stable. It is more common, has cubic crystal structure and at 195.2 K (−78.0 °C), it transforms into β-form, which has hexagonal crystal structure. These forms differ in terms of

1566-512: Is the least reactive allotrope and the thermodynamically stable form below 550 °C (1,022 °F). It is also known as β-metallic phosphorus and has a structure somewhat resembling that of graphite . It is obtained by heating white phosphorus under high pressures (about 12,000 standard atmospheres or 1.2 gigapascals). It can also be produced at ambient conditions using metal salts, e.g. mercury, as catalysts. In appearance, properties, and structure, it resembles graphite , being black and flaky,

1624-728: Is today the chief commercial source of this element. According to the US Geological Survey (USGS) , about 50 percent of the global phosphorus reserves are in Amazigh nations like Morocco , Algeria and Tunisia . 85% of Earth's known reserves are in Morocco with smaller deposits in China , Russia , Florida , Idaho , Tennessee , Utah , and elsewhere. Albright and Wilson in the UK and their Niagara Falls plant, for instance, were using phosphate rock in

1682-406: Is triggered by the same forces that affect other structures, i.e., pressure , light , and temperature . Therefore, the stability of the particular allotropes depends on particular conditions. For instance, iron changes from a body-centered cubic structure ( ferrite ) to a face-centered cubic structure ( austenite ) above 906 °C, and tin undergoes a modification known as tin pest from

1740-524: The Greek words (φῶς = light, φέρω = carry), which roughly translates as light-bringer or light carrier. (In Greek mythology and tradition, Augerinus (Αυγερινός = morning star, still in use today), Hesperus or Hesperinus (΄Εσπερος or Εσπερινός or Αποσπερίτης = evening star, still in use today) and Eosphorus (Εωσφόρος = dawnbearer, not in use for the planet after Christianity) are close homologues, and also associated with Phosphorus-the-morning-star ). According to

1798-419: The phosphide ion, P . These compounds react with water to form phosphine . Other phosphides , for example Na 3 P 7 , are known for these reactive metals. With the transition metals as well as the monophosphides there are metal-rich phosphides, which are generally hard refractory compounds with a metallic lustre, and phosphorus-rich phosphides which are less stable and include semiconductors. Schreibersite

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1856-557: The 1890s and 1900s from Tennessee, Florida, and the Îles du Connétable ( guano island sources of phosphate); by 1950, they were using phosphate rock mainly from Tennessee and North Africa. Organic sources, namely urine , bone ash and (in the latter 19th century) guano , were historically of importance but had only limited commercial success. As urine contains phosphorus, it has fertilising qualities which are still harnessed today in some countries, including Sweden , using methods for reuse of excreta . To this end, urine can be used as

1914-497: The Oxford English Dictionary, the correct spelling of the element is phosphorus . The word phosphorous is the adjectival form of the P valence: so, just as sulfur forms sulfurous and sulfuric compounds, phosphorus forms phosphorous compounds (e.g., phosphorous acid ) and P valence phosphoric compounds (e.g., phosphoric acids and phosphates ). The discovery of phosphorus, the first element to be discovered that

1972-466: The acceptance of Avogadro's hypothesis in 1860, it was understood that elements could exist as polyatomic molecules, and two allotropes of oxygen were recognized as O 2 and O 3 . In the early 20th century, it was recognized that other cases such as carbon were due to differences in crystal structure. By 1912, Ostwald noted that the allotropy of elements is just a special case of the phenomenon of polymorphism known for compounds, and proposed that

2030-460: The aid of his assistant, Ambrose Godfrey-Hanckwitz . Godfrey later made a business of the manufacture of phosphorus. Boyle states that Kraft gave him no information as to the preparation of phosphorus other than that it was derived from "somewhat that belonged to the body of man". This gave Boyle a valuable clue, so that he, too, managed to make phosphorus, and published the method of its manufacture. Later he improved Brand's process by using sand in

2088-425: The air. In fact, this process is caused by the phosphorus reacting with oxygen in the air; in a sealed container, this process will eventually stop when all the oxygen in the container is 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 pressures at which it does. Heat can be applied to drive the reaction at higher pressures. In 1974,

2146-638: The chloride groups are replaced by alkoxide (RO ), a family of polymers is produced with potentially useful properties. Phosphorus forms a wide range of sulfides, where the phosphorus can be in P(V), P(III) or other oxidation states. The three-fold symmetric P 4 S 3 is used in strike-anywhere matches. P 4 S 10 and P 4 O 10 have analogous structures. Mixed oxyhalides and oxyhydrides of phosphorus(III) are almost unknown. Compounds with P-C and P-O-C bonds are often classified as organophosphorus compounds. They are widely used commercially. The PCl 3 serves as

2204-491: The color darkens (see infobox images); the resulting product is more stable and does not spontaneously ignite in air. Violet phosphorus is a form of phosphorus that can be produced by day-long annealing of red phosphorus above 550 °C. In 1865, Hittorf discovered that when phosphorus was recrystallised from molten lead , a red/purple form is obtained. Therefore, this form is sometimes known as "Hittorf's phosphorus" (or violet or α-metallic phosphorus). Black phosphorus

2262-481: The concept of nanoallotropy was proposed. Nanoallotropes, or allotropes of nanomaterials , are nanoporous materials that have the same chemical composition (e.g., Au), but differ in their architecture at the nanoscale (that is, on a scale 10 to 100 times the dimensions of individual atoms). Such nanoallotropes may help create ultra-small electronic devices and find other industrial applications. The different nanoscale architectures translate into different properties, as

2320-413: The dark without burning. Although the term phosphorescence is derived from phosphorus, the reaction that gives phosphorus its glow is properly called chemiluminescence (glowing due to a cold chemical reaction), not phosphorescence (re-emitting light that previously fell onto a substance and excited it). There are 22 known isotopes of phosphorus, ranging from P to P . Only P

2378-449: The early Earth. Phosphorus has a concentration in the Earth's crust of about one gram per kilogram (compare copper at about 0.06 grams). It is not found free in nature, but is widely distributed in many minerals , usually as phosphates. Inorganic phosphate rock , which is partially made of apatite (a group of minerals being, generally, pentacalcium triorthophosphate fluoride (hydroxide)),

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2436-523: The glow was explained by R. J. van Zee and A. U. Khan. A reaction with oxygen takes place at the surface of the solid (or liquid) phosphorus, forming the short-lived molecules HPO and P 2 O 2 that both emit visible light. The reaction is slow and only very little of the intermediates are required to produce the luminescence, hence the extended time the glow continues in a stoppered jar. Since its discovery, phosphors and phosphorescence were used loosely to describe substances that shine in

2494-744: The metallic elements that occur in nature in significant quantities (56 up to U, without Tc and Pm), almost half (27) are allotropic at ambient pressure: Li, Be, Na, Ca, Ti, Mn, Fe, Co, Sr, Y, Zr, Sn, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Yb, Hf, Tl, Th, Pa and U. Some phase transitions between allotropic forms of technologically relevant metals are those of Ti at 882 °C, Fe at 912 °C and 1394 °C, Co at 422 °C, Zr at 863 °C, Sn at 13 °C and U at 668 °C and 776 °C.   Most stable structure under standard conditions.   Structures stable below room temperature.   Structures stable above room temperature.   Structures stable above atmospheric pressure. In 2017,

2552-488: The most important allotrope is white phosphorus , often abbreviated WP. White phosphorus is a soft, waxy molecular solid composed of P 4 tetrahedra . This P 4 tetrahedron is also present in liquid and gaseous phosphorus up to the temperature of 800 °C (1,500 °F; 1,100 K) when it starts decomposing to P 2 molecules. The nature of bonding in this P 4 tetrahedron can be described by spherical aromaticity or cluster bonding, that

2610-439: The phosphorus atoms and at the vertices. White phosphorus is a napalm additive, and the characteristic odour of combustion is garlicky. White phosphorus is insoluble in water but soluble in carbon disulfide. Thermal decomposition of P 4 at 1100 K gives diphosphorus , P 2 . This species is not stable as a solid or liquid. The dimeric unit contains a triple bond and is analogous to N 2 . It can also be generated as

2668-437: The phosphorus that plants remove from the soil, and its annual demand is rising nearly twice as fast as the growth of the human population. Other applications include organophosphorus compounds in detergents , pesticides , and nerve agents . Phosphorus has several allotropes that exhibit strikingly diverse properties. The two most common allotropes are white phosphorus and red phosphorus. For both pure and applied uses,

2726-434: The process produced a white material that glowed in the dark and burned brilliantly. It was named phosphorus mirabilis ("miraculous bearer of light"). Brand's process originally involved letting urine stand for days until it gave off a terrible stench. Then he boiled it down to a paste, heated this paste to a high temperature, and led the vapours through water, where he hoped they would condense to gold. Instead, he obtained

2784-399: The reaction (still using urine as base material), Allotropy The term allotropy is used for elements only, not for compounds . The more general term, used for any compound, is polymorphism , although its use is usually restricted to solid materials such as crystals. Allotropy refers only to different forms of an element within the same physical phase (the state of matter, such as

2842-427: The relative orientations of the constituent P 4 tetrahedra. White phosphorus is the least stable, the most reactive, the most volatile , the least dense and the most toxic of the allotropes. White phosphorus gradually changes to red phosphorus, accelerated by light and heat. Samples of white phosphorus almost always contain some red phosphorus and accordingly appear yellow. For this reason, white phosphorus that

2900-576: The same amount of phosphorus. Brand at first tried to keep the method secret, but later sold the recipe for 200 thalers to Johann Daniel Kraft ( de ) from Dresden. Kraft toured much of Europe with it, including England, where he met with Robert Boyle . The secret—that the substance was made from urine—leaked out, and Johann Kunckel (1630–1703) was able to reproduce it in Sweden (1678). Later, Boyle in London (1680) also managed to make phosphorus, possibly with

2958-542: The solid, liquid and gaseous states. Other elements do not maintain distinct allotropes in different physical phases; for example, phosphorus has numerous solid allotropes , which all revert to the same P 4 form when melted to the liquid state. The concept of allotropy was originally proposed in 1840 by the Swedish scientist Baron Jöns Jakob Berzelius (1779–1848). The term is derived from Greek άλλοτροπἱα (allotropia)  'variability, changeableness'. After

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3016-428: The terms allotrope and allotropy be abandoned and replaced by polymorph and polymorphism. Although many other chemists have repeated this advice, IUPAC and most chemistry texts still favour the usage of allotrope and allotropy for elements only. Allotropes are different structural forms of the same element and can exhibit quite different physical properties and chemical behaviours. The change between allotropic forms

3074-556: The treatment of arterial stenosis but is no longer indicated at this time. Phosphorus Phosphorus is a chemical element ; it has symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus , but because it is highly reactive , phosphorus is never found as a free element on Earth. It has a concentration in the Earth's crust of about 0.1%, less abundant than hydrogen but more than manganese . In minerals, phosphorus generally occurs as phosphate . Elemental phosphorus

3132-472: The white (but not red) phosphorus – a process now called chemiluminescence . Phosphorus is classified as a pnictogen , together with nitrogen , arsenic , antimony , bismuth , and moscovium . Phosphorus is an element essential to sustaining life largely through phosphates , compounds containing the phosphate ion, PO 4 . Phosphates are a component of DNA , RNA , ATP , and phospholipids , complex compounds fundamental to cells . Elemental phosphorus

3190-439: The yellowish liquids PCl 3 and PBr 3 , and the solid PI 3 . These materials are moisture sensitive, hydrolysing to give phosphorous acid . The trichloride, a common reagent, is produced by chlorination of white phosphorus: The trifluoride is produced from the trichloride by halide exchange. PF 3 is toxic because it binds to haemoglobin . Phosphorus(III) oxide , P 4 O 6 (also called tetraphosphorus hexoxide)

3248-592: Was first isolated as white phosphorus in 1669. In white phosphorus, phosphorus atoms are arranged in groups of 4, written as P 4 . White phosphorus emits a faint glow when exposed to oxygen – hence, a name, taken from Greek mythology, Φωσφόρος meaning 'light-bearer' (Latin Lucifer ), referring to the " Morning Star ", the planet Venus . The term phosphorescence , meaning glow after illumination, has its origin in phosphorus, although phosphorus itself does not exhibit phosphorescence: phosphorus glows due to oxidation of

3306-410: Was first isolated from human urine , and bone ash was an important early phosphate source. Phosphate mines contain fossils because phosphate is present in the fossilized deposits of animal remains and excreta. Low phosphate levels are an important limit to growth in a number of plant ecosystems. The vast majority of phosphorus compounds mined are consumed as fertilisers . Phosphate is needed to replace

3364-539: Was not known since ancient times, is credited to the German alchemist Hennig Brand in 1669, although others might have discovered phosphorus around the same time. Brand experimented with urine , which contains considerable quantities of dissolved phosphates from normal metabolism. Working in Hamburg , Brand attempted to create the fabled philosopher's stone through the distillation of some salts by evaporating urine, and in

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