query: What is phosphorus?

title: Phosphorus deficiency

text: acidity, measured on the pH scale, partially dictates what chemical arrangements that phosphorus forms. Between pH 6 and 7, phosphorus makes the fewest number of bonds which render the nutrient unusable to plants. At this range of acidity the likeliness of phosphorus uptake is increased and the likeliness of phosphorus deficiency is decreased. Another component in the prevention and treatment of phosphorus is the plant’s disposition to absorb nutrients. Plant species and different plants within in the same species react differently to low levels of phosphorus in soil. Greater expansion of root systems generally correlate to greater nutrient uptake. Plants

title: Phosphorus

text: Phosphorus Phosphorus is a chemical element with 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 one gram per kilogram (compare copper at about 0.06 grams). With few exceptions, minerals containing phosphorus are in the maximally oxidized state as inorganic phosphate rocks. Elemental phosphorus was first isolated (as white phosphorus) in 1669 and emitted a faint glow when exposed to oxygen – hence the name,

title: Phosphorus

text: red and white phosphorus were designated by the United States Drug Enforcement Administration as List I precursor chemicals under 21 CFR 1310.02 effective on November 17, 2001. In the United States, handlers of red or white phosphorus are subject to stringent regulatory controls. Phosphorus Phosphorus is a chemical element with 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 one gram per kilogram (compare copper

title: Phosphorus

text: and calcium sulfate dihydrate (CaSO·2HO) produced reacting sulfuric acid and water with calcium phosphate. Processing phosphate minerals with sulfuric acid for obtaining fertiliser is so important to the global economy that this is the primary industrial market for sulfuric acid and the greatest industrial use of elemental sulfur. White phosphorus is widely used to make organophosphorus compounds through intermediate phosphorus chlorides and two phosphorus sulfides, phosphorus pentasulfide and phosphorus sesquisulfide. Organophosphorus compounds have many applications, including in plasticisers, flame retardants, pesticides, extraction agents, nerve agents and water treatment. Phosphorus is also an important component in steel production, in the making

title: Phosphorus

text: has several allotropes that exhibit strikingly different properties. The two most common allotropes are white phosphorus and red phosphorus. From the perspective of applications and chemical literature, the most important form of elemental phosphorus is white phosphorus, often abbreviated as WP. It is a soft, waxy solid which consists of tetrahedral molecules, in which each atom is bound to the other three atoms by a single bond. This tetrahedron is also present in liquid and gaseous phosphorus up to the temperature of when it starts decomposing to molecules. White phosphorus exists in two crystalline forms: α (alpha) and β (beta).

title: Phosphorus

text: elemental phosphorus is extracted includes applying at high temperatures (1500 °C): Historically, before the development of mineral-based extractions, white phosphorus was isolated on an industrial scale from bone ash. In this process, the tricalcium phosphate in bone ash is converted to monocalcium phosphate with sulfuric acid: Monocalcium phosphate is then dehydrated to the corresponding metaphosphate: When ignited to a white heat with charcoal, calcium metaphosphate yields two-thirds of its weight of white phosphorus while one-third of the phosphorus remains in the residue as calcium orthophosphate: Phosphorus is an essential plant nutrient (often the limiting nutrient), and the bulk of all

title: Phosphorus deficiency

text: into the soil however does not ensure the alleviation of phosphorus deficiency. There must be phosphorus in the soil, but the phosphorus must also be absorbed by the plant. The uptake of phosphorus is limited by the chemical form in which the phosphorus is available in the soil. A large percentage of phosphorus in soil is present in chemical compounds that plants are incapable of absorbing. Phosphorus must be present in soil in specific chemical arrangements to be usable as plant nutrients. Facilitation of usable phosphorus in soil can be optimized by maintaining soil within a specified pH range. Soil

title: Phosphorus

text: material), Robert Boyle was the first to use phosphorus to ignite sulfur-tipped wooden splints, forerunners of our modern matches, in 1680. Phosphorus was the 13th element to be discovered. For this reason, and due to its use in explosives, poisons and nerve agents, it is sometimes referred to as "the Devil's element". In 1769, Johan Gottlieb Gahn and Carl Wilhelm Scheele showed that calcium phosphate () is found in bones, and they obtained elemental phosphorus from bone ash. Antoine Lavoisier recognised phosphorus as an element in 1777. Bone ash was the major source of phosphorus until the 1840s. The method

title: Phosphorus deficiency

text: Phosphorus deficiency Phosphorus deficiency is a plant disorder associated with insufficient supply of phosphorus. Phosphorus refers here to salts of phosphates (PO), monohydrogen phosphate (HPO), and dihydrogen phosphate (HPO). These anions readily interconvert, and the predominant species is determined by the pH of the solution or soil. Phosphates are required for the biosynthesis of genetic material as well as ATP, essential for life. Phosphorus deficiency can be controlled by applying sources of phosphorus such as bone meal, rock phosphate, manure, and phosphate-fertilizers. In plants, Phosphorus (P) is considered second to nitrogen as the most essential nutrient to ensure health and

title: Phosphorus cycle

text: slows soil microbial growth - as shown in studies of soil microbial biomass. Soil microorganisms act as both sinks and sources of available phosphorus in the biogeochemical cycle. Locally, transformations of phosphorus are chemical, biological and microbiological: the major long-term transfers in the global cycle, however, are driven by tectonic movements in geologic time. Humans have caused major changes to the global phosphorus cycle through shipping of phosphorus minerals, and use of phosphorus fertilizer, and also the shipping of food from farms to cities, where it is lost as effluent. Phosphorus is an essential nutrient for plants and animals. Phosphorus

title: Phosphorus halide

text: Berry pseudorotation mechanism. Phosphorus pentachloride, phosphorus pentabromide, and phosphorus heptabromide are ionic in the solid and liquid states; PCl is formulated as PClPCl, but in contrast, PBr is formulated as PBr Br, and PBr is formulated as PBr Br. They are widely used as chlorinating and brominating agents in organic chemistry. The phosphorus(III) halides are the best known of the three series. They are usually prepared by direct reaction of the elements, or by transhalogenation. Phosphorus trifluoride is used as a ligand in coordination chemistry, where it resembles carbon monoxide. Phosphorus trichloride is a major industrial chemical and widely used

title: Phosphorus deficiency

text: degree to this color change is an indicator of phosphorus concentration. To apply this testing method on phosphorus deficiency, the measured phosphorus concentration must be compared to known values. Most plants have established and thoroughly tested optimal soil conditions. If the concentration of phosphorus measured from the colorimeter test is significantly lower than the plant’s optimal soil levels, then it is likely the plant is phosphorus deficient. The soil testing with colorimetric analysis, while widely used, can be subject to diagnostic problems as a result of interference from other present compounds and elements. Additional phosphorus detection methods such as spectral

title: Phosphorus deficiency

text: function. Phosphorus is used by plants in numerous processes such as photophosphorylation, genetic transfer, the transportation of nutrients, and phospholipid cell membranes. Within a plant cell these functions are imperative for function, in photophosphorylation for example the creation of stored energy in plants is a result of a chemical reaction including phosphorus. Phosphorus is a key molecular component of genetic reproduction. When phosphorus is present in inadequate levels, genetic processes such as cell division and plant growth are impaired. Hence, phosphorus deficient plants may mature at a slower rate than plants with adequate amounts of phosphorus. The stunted growth induced

title: Phosphorus

text: Elemental phosphorus 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 some aquatic systems. The vast majority of phosphorus compounds mined are consumed as fertilisers. Phosphate is needed to replace 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

title: Phosphorus cycle

text: and maintenance of healthy ecosystems. Humans have greatly influenced the phosphorus cycle by mining phosphorus, converting it to fertilizer, and by shipping fertilizer and products around the globe. Transporting phosphorus in food from farms to cities has made a major change in the global Phosphorus cycle. However, excessive amounts of nutrients, particularly phosphorus and nitrogen, are detrimental to aquatic ecosystems. Waters are enriched in phosphorus from farms' run-off, and from effluent that is inadequately treated before it is discharged to waters. Natural eutrophication is a process by which lakes gradually age and become more productive and may take thousands of

title: Phosphorus deficiency

text: within a species that have larger roots are genetically advantaged and less prone to phosphorus deficiency. These plants can be cultivated and bred as a long term phosphorus deficiency prevention method. In conjunction to root size, other genetic root adaptations to low phosphorus conditions such as mycorrhizal symbioses have been found to increase nutrient intake. These biological adaptations to roots work to maintain the levels of vital nutrients. In larger commercial agriculture settings, variation of plants to adopt these desirable phosphorus intake adaptations may be a long-term phosphorus deficiency correction method. Phosphorus deficiency Phosphorus deficiency is a plant disorder associated

title: Phosphorus

text: be exposed to phosphorus in the workplace by inhalation, ingestion, skin contact, and eye contact. The Occupational Safety and Health Administration (OSHA) has set the phosphorus exposure limit (Permissible exposure limit) in the workplace at 0.1 mg/m over an 8-hour workday. The National Institute for Occupational Safety and Health (NIOSH) has set a Recommended exposure limit (REL) of 0.1 mg/m over an 8-hour workday. At levels of 5 mg/m, phosphorus is immediately dangerous to life and health. Phosphorus can reduce elemental iodine to hydroiodic acid, which is a reagent effective for reducing ephedrine or pseudoephedrine to methamphetamine. For this reason,

title: Phosphorus

text: (herbicides, insecticides, fungicides, etc.) and weaponised as nerve agents against enemy humans. Most inorganic phosphates are relatively nontoxic and essential nutrients. The white phosphorus allotrope presents a significant hazard because it ignites in air and produces phosphoric acid residue. Chronic white phosphorus poisoning leads to necrosis of the jaw called "phossy jaw". White phosphorus is toxic, causing severe liver damage on ingestion and may cause a condition known as "Smoking Stool Syndrome". In the past, external exposure to elemental phosphorus was treated by washing the affected area with 2% copper sulfate solution to form harmless compounds that are then washed

title: Phosphorus

text: of phosphor bronze, and in many other related products. Phosphorus is added to metallic copper during its smelting process to react with oxygen present as an impurity in copper and to produce phosphorus-containing copper (CuOFP) alloys with a higher hydrogen embrittlement resistance than normal copper. The first striking match with a phosphorus head was invented by Charles Sauria in 1830. These matches (and subsequent modifications) were made with heads of white phosphorus, an oxygen-releasing compound (potassium chlorate, lead dioxide, or sometimes nitrate), and a binder. They were poisonous to the workers in manufacture, sensitive to storage conditions, toxic if ingested,

title: Phosphorus cycle

text: rate of their degradation to generate free phosphate. There are various enzymes such as phosphatases, nucleases and phytase involved for the degradation. Some of the abiotic pathways in the environment studied are hydrolytic reactions and photolytic reactions. Enzymatic hydrolysis of organic phosphorus is an essential step in the biogeochemical phosphorus cycle, including the phosphorus nutrition of plants and microorganisms and the transfer of organic phosphorus from soil to bodies of water. Many organisms rely on the soil derived phosphorus for their phosphorus nutrition. Nutrients are important to the growth and survival of living organisms, and hence, are essential for development

title: White phosphorus munitions

text: phosphorus against personnel. Though white phosphorus is still used in modern armed conflict, its use in incendiary weapons is regulated by international humanitarian law, or the law of war. White phosphorus munitions White phosphorus is a material made from a common allotrope of the chemical element phosphorus that is used in smoke, tracer illumination, and incendiary munitions. Other common names include WP and the slang term "Willie Pete" or "Willie Peter" derived from William Peter, the World War II phonetic alphabet for "WP", which is still sometimes used in military jargon. As an incendiary weapon, white phosphorus is pyrophoric (self-igniting),

title: Phosphorus

text: "Phosphorus" in Ancient Greece was the name for the planet Venus and is derived from 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-planet). According to the Oxford English Dictionary, the correct spelling of the element is phosphorus. The word phosphorous is

title: Allotropes of phosphorus

text: Allotropes of phosphorus Elemental phosphorus can exist in several allotropes, the most common of which are white and red solids. Solid violet and black allotropes are also known. Gaseous phosphorus exists as diphosphorus and atomic phosphorus. White phosphorus, yellow phosphorus or simply tetraphosphorus (P) exists as molecules made up of four atoms in a tetrahedral structure. The tetrahedral arrangement results in ring strain and instability. The molecule is described as consisting of six single P–P bonds. Two different crystalline forms are known. The α form is defined as the standard state of the element, but is actually metastable under standard

title: Phosphorus cycle

text: soluble. Unlike other cycles, P is not normally found in the air as a gas; it only occurs under highly reducing conditions as the gas phosphine PH. The availability of phosphorus in an ecosystem is restricted by the rate of release of this element during weathering. The release of phosphorus from apatite dissolution is a key control on ecosystem productivity. The primary mineral with significant phosphorus content, apatite [Ca(PO)OH] undergoes carbonation. Little of this released phosphorus is taken up by biota (organic form), whereas a larger proportion reacts with other soil minerals. This leads to precipitation into unavailable forms in

title: Phosphorus Rex

text: Batman later interrogated Phosphorus Rex into giving him the identity of the Circus of Strange's leader. What Phosphorus Rex told Batman led him to Professor Pyg. In September 2011, The New 52 rebooted DC's continuity. In this new timeline, Phosphorus Rex and Professor Pyg are first seen as inmates of Arkham Asylum. At the time when Batman and Nightwing arrived at Arkham Asylum to capture a corrupt guard who ended up releasing the inmates, Phosphorus Rex is among those who take part in the break-out attempt only to be thwarted by Batman and Nightwing. Phosphorus Rex has pyrokinetic abilities. He

title: Phosphorus

text: 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 is the least reactive allotrope and the thermodynamically stable form below . 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

title: Phosphorus

text: phosphorus may be formed by heating white phosphorus to or by exposing white phosphorus to sunlight. Phosphorus after this treatment 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 , though it is more stable than white phosphorus, which ignites at about . After prolonged heating or storage, the color darkens (see infobox images); the resulting product

title: Phosphorus

text: that is aged or otherwise impure (e.g., weapons-grade, not lab-grade WP) is also called yellow phosphorus. When exposed to oxygen, white phosphorus glows in the dark with a very faint tinge of green and blue. It is highly flammable and pyrophoric (self-igniting) upon contact with air. Owing to its pyrophoricity, white phosphorus is used as an additive in napalm. The odour of combustion of this form has a characteristic garlic smell, and samples are commonly coated with white "phosphorus pentoxide", which consists of tetrahedra with oxygen inserted between the phosphorus atoms and at their vertices. White phosphorus is insoluble in

title: Phosphorus

text: At room temperature, the α-form is stable, which is more common and it has cubic crystal structure and at , it transforms into β-form, which has hexagonal crystal structure. These forms differ in terms of the relative orientations of the constituent P 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. This transformation is accelerated by light and heat, and samples of white phosphorus almost always contain some red phosphorus and accordingly appear yellow. For this reason, white phosphorus

title: White phosphorus munitions

text: not to use water from wells, nor eat vegetables from their gardens or drink milk from their cows (later this advice was revoked). On 18 July 2007, it was reported that NATO was watching the toxic cloud movement. In its early statements the Israeli military denied using white phosphorus, saying "The IDF acts only in accordance with what is permitted by international law and does not use white phosphorus." Numerous reports from human right groups during the war indicated that white phosphorus shells were being used by Israel in populated areas. United States based human rights organisation Human Rights Watch

title: Phosphorus

text: plant uptake from soil systems. Phosphorus is a limiting factor in many ecosystems; that is, the scarcity of phosphorus limits the rate of organism growth. An excess of phosphorus can also be problematic, especially in aquatic systems where eutrophication sometimes leads to algal blooms. The U.S. Institute of Medicine (IOM) updated Estimated Average Requirements (EARs) and Recommended Dietary Allowances (RDAs) for phosphorus in 1997. If there is not sufficient information to establish EARs and RDAs, an estimate designated Adequate Intake (AI) is used instead. The current EAR for phosphorus for people ages 19 and up is 580 mg/day. The RDA

title: Phosphorus-32

text: Phosphorus-32 Phosphorus-32 is a radioactive isotope of phosphorus. The nucleus of phosphorus-32 contains 15 protons and 17 neutrons, one more neutron than the most common isotope of phosphorus, phosphorus-31. Phosphorus-32 only exists in small quantities on Earth as it has a short half-life of 14.29 days and so decays rapidly. Phosphorus is found in many organic molecules and so phosphorus-32 has many applications in medicine, biochemistry and molecular biology where it can be used to trace phosphorylated molecules, e.g. in elucidating metabolic pathways, and radioactively label DNA. Phosphorus has a short half-life of 14.29 days and decays into sulfur-32 by

title: Phosphorus

text: taken from Greek mythology, meaning "light-bearer" (Latin "Lucifer"), referring to the "Morning Star", the planet Venus. The term "phosphorescence", meaning glow after illumination, derives from this property of phosphorus, although the word has since been used for a different physical process that produces a glow. The glow of phosphorus is caused by oxidation of the white (but not red) phosphorus — a process now called chemiluminescence. Together with nitrogen, arsenic, antimony, and bismuth, phosphorus is classified as a pnictogen. Phosphorus is essential for life. Phosphates (compounds containing the phosphate ion, PO) are a component of DNA, RNA, ATP, and phospholipids.

title: Phosphorus sulfide

text: in 1:2 mole ratio, where PS is reversibly formed: PS is one of the most stable phosphorus sulfides. It is most easily made by heating white phosphorus with sulfur above 570 K in an evacuated tube. Phosphorus sulfide Phosphorus sulfides comprise a family of inorganic compounds containing only phosphorus and sulfur. These compounds have the formula PS with "x" ≤ 10. Two are of commercial significance, phosphorus pentasulfide (PS), which is made on a kiloton scale for the production of other organosulfur compounds, and phosphorus sesquisulfide (PS), used in the production of "strike anywhere matches". There are several other phosphorus

title: Phosphorus-32

text: perspex radiation shield to protect the body. Dense shielding, such as lead, is less effective due to the high-energy bremsstrahlung produced by the interaction of the beta particle and the shielding. Because the beta radiation from phosphorus-32 is blocked by around 1 m of air it is also advisable to wear dosimeters on the parts of the body, for example the fingers, which come into close contact with the phosphorus-32-containing sample. Phosphorus-32 Phosphorus-32 is a radioactive isotope of phosphorus. The nucleus of phosphorus-32 contains 15 protons and 17 neutrons, one more neutron than the most common isotope of phosphorus, phosphorus-31.

title: Phosphorus trichloride

text: time-weighted average of 8 hours. Additionally, PCl has been designated IDLH with a maximum exposure limit at 25 ppm. Phosphorus trichloride was first prepared in 1808 by the French chemists Joseph Louis Gay-Lussac and Louis Jacques Thénard by heating calomel (HgCl) with phosphorus. Later during the same year, the English chemist Humphry Davy produced phosphorus trichloride by burning phosphorus in chlorine gas. Phosphorus trichloride Phosphorus trichloride is a chemical compound of phosphorus and chlorine, having the chemical formula PCl. It has a trigonal pyramidal shape. It is the most important of the three phosphorus chlorides. It is an important industrial

title: Phosphorus

text: 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 PH. The highly flammable gas diphosphine (PH) is an analogue of hydrazine. Phosphorous 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

title: Phosphorus

text: of phosphorus, about 85–90% in bones and teeth in the form of apatite, and the remainder in soft tissues and extracellular fluids (~1%). The phosphorus content increases from about 0.5 weight% in infancy to 0.65–1.1 weight% in adults. Average phosphorus concentration in the blood is about 0.4 g/L, about 70% of that is organic and 30% inorganic phosphates. An adult with healthy diet consumes and excretes about 1–3 grams of phosphorus per day, with consumption in the form of inorganic phosphate and phosphorus-containing biomolecules such as nucleic acids and phospholipids; and excretion almost exclusively in the form of phosphate ions

title: Phosphorus cycle

text: water ecosystems by inducing anoxic conditions. Phosphorus cycle The phosphorus cycle is the biogeochemical cycle that describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere. Unlike many other biogeochemical cycles, the atmosphere does not play a significant role in the movement of phosphorus, because phosphorus and phosphorus-based compounds are usually solids at the typical ranges of temperature and pressure found on Earth. The production of phosphine gas occurs in only specialized, local conditions. On the land, phosphorus gradually becomes less available to plants over thousands of years, because it is slowly lost in runoff. Low concentration of phosphorus

title: Phosphorus cycle

text: Phosphorus cycle The phosphorus cycle is the biogeochemical cycle that describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere. Unlike many other biogeochemical cycles, the atmosphere does not play a significant role in the movement of phosphorus, because phosphorus and phosphorus-based compounds are usually solids at the typical ranges of temperature and pressure found on Earth. The production of phosphine gas occurs in only specialized, local conditions. On the land, phosphorus gradually becomes less available to plants over thousands of years, because it is slowly lost in runoff. Low concentration of phosphorus in soils reduces plant growth, and

title: Phosphorus Rex

text: enforcer. Tobias Whale is accidentally pinned down by a shelf during Phosphorus Rex's fiery attack on Batman and Katana. Batman and Katana managed to defeat Tobias Whale and Phosphorus Rex who are then arrested by the police. In the episode "Reckoning", Tobias Whale and Phosphorus Rex are some of the Blackgate Penitentiary inmates rallied by Ra's al Ghul to capture and bring Batman to him. Phosphorus Rex Phosphorus Rex is a supervillain in DC Comics. Phosphorus Rex first appeared in "Batman" #666 and was created by Grant Morrison. Phosphorus Rex is a fiery member of the Circus of Strange. After

title: Phosphorus

text: 2020 for large companies and January 1, 2021 for small companies. The main food sources for phosphorus are the same as those containing protein, although proteins do not contain phosphorus. For example, milk, meat, and soya typically also have phosphorus. As a rule, if a diet has sufficient protein and calcium, the amount of phosphorus is probably sufficient. Organic compounds of phosphorus form a wide class of materials; many are required for life, but some are extremely toxic. Fluorophosphate esters are among the most potent neurotoxins known. A wide range of organophosphorus compounds are used for their toxicity as pesticides

title: Phosphorus

text: fertiliser production. Phosphate rock production greatly increased after World War II, and remains the primary global source of phosphorus and phosphorus chemicals today. See the article on peak phosphorus for more information on the history and present state of phosphate mining. Phosphate rock remains a feedstock in the fertiliser industry, where it is treated with sulfuric acid to produce various "superphosphate" fertiliser products. White phosphorus was first made commercially in the 19th century for the match industry. This used bone ash for a phosphate source, as described above. The bone-ash process became obsolete when the submerged-arc furnace for phosphorus production

title: White phosphorus munitions

text: said incendiary shells exploded over populated civilian areas, including a crowded Palestinian refugee camp and a United Nations school where civilians were seeking refuge. Human Rights Watch said that white phosphorus injuries were suspected in the cases of ten burn victims. The International Red Cross stated that phosphorus weapons had been used in the conflict but would not comment publicly on the legality of Israel's use of the weapon, pending further investigation, contrary to what had been attributed to the ICRC in a number of media reports. The ICRC had previously said it had no evidence white phosphorus was used

title: Phosphorus

text: phosphorus production is in concentrated phosphoric acids for agriculture fertilisers, containing as much as 70% to 75% PO. Its annual demand is rising nearly twice as fast as the growth of the human population. That led to large increase in phosphate (PO) production in the second half of the 20th century. Artificial phosphate fertilisation is necessary because phosphorus is essential to all living organisms; natural phosphorus-bearing compounds are mostly insoluble and inaccessible to plants, and the natural cycle of phosphorus is very slow. Fertiliser is often in the form of superphosphate of lime, a mixture of calcium dihydrogen phosphate (Ca(HPO)),

title: Phosphorus sulfide

text: Phosphorus sulfide Phosphorus sulfides comprise a family of inorganic compounds containing only phosphorus and sulfur. These compounds have the formula PS with "x" ≤ 10. Two are of commercial significance, phosphorus pentasulfide (PS), which is made on a kiloton scale for the production of other organosulfur compounds, and phosphorus sesquisulfide (PS), used in the production of "strike anywhere matches". There are several other phosphorus sulfides in addition to PS and PS. Six of these phosphorus sulfides exist as isomers: PS, PS, PS, PS, PS, and PS. These isomers are distinguished by Greek letter prefixes. The prefix is based on the

title: Phosphorus

text: The fluoride is sometimes recovered for use in water fluoridation. More problematic is a "mud" containing significant amounts of white phosphorus. Production of white phosphorus is conducted in large facilities in part because it is energy intensive. The white phosphorus is transported in molten form. Some major accidents have occurred during transportation; train derailments at Brownston, Nebraska and Miamisburg, Ohio led to large fires. The worst incident in recent times was an environmental contamination in 1968 when the sea was polluted from spillage and/or inadequately treated sewage from a white phosphorus plant at Placentia Bay, Newfoundland. Another process by which

title: Phosphorus

text: particularly important. The PN molecule is considered unstable, but is a product of crystalline phosphorus nitride decomposition at 1100 K. Similarly, HPN is considered unstable, and phosphorus nitride halogens like FPN, ClPN, BrPN, and IPN oligomerise into cyclic Polyphosphazenes. For example, compounds of the formula (PNCl) exist mainly as rings such as the trimer hexachlorophosphazene. The phosphazenes arise by treatment of phosphorus pentachloride with ammonium chloride:PCl + NHCl → 1/"n" (NPCl) + 4 HClWhen 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

title: Phosphorus cycle

text: Weathering of rocks and minerals release phosphorus in a soluble form where it is taken up by plants, and it is transformed into organic compounds. The plants may then be consumed by herbivores and the phosphorus is either incorporated into their tissues or excreted. After death, the animal or plant decays, and phosphorus is returned to the soil where a large part of the phosphorus is transformed into insoluble compounds. Runoff may carry a small part of the phosphorus back to the ocean. Generally with time (thousands of years) soils become deficient in phosphorus leading to ecosystem retrogression. The primary

title: Phosphorus pentasulfide

text: Phosphorus pentasulfide Phosphorus pentasulfide is the inorganic compound with the formula PS or dimer PS. This yellow solid is the one of two phosphorus sulfides of commercial value. Samples often appear greenish-gray due to impurities. It is soluble in carbon disulfide but reacts with many other solvents such as alcohols, DMSO, and DMF. Its tetrahedral molecular structure is similar to that of adamantane and almost identical to the structure of phosphorus pentoxide. Phosphorus pentasulfide is obtained by the reaction of liquid white phosphorus (P) with sulfur above 300 °C. The first synthesis of PS by Berzelius in 1843 was by

title: Peak phosphorus

text: Peak phosphorus Peak phosphorus is a concept to describe the point in time when humanity reaches the maximum global production rate of phosphorus as an industrial and commercial raw material. The term is used in an equivalent way to the better-known term peak oil. The issue was raised as a debate on whether a "peak phosphorus" was imminent or not around 2010, but was largely dismissed after USGS and other organizations increased the world estimates on available phosphorus resources. Phosphorus is a finite (limited) resource that is widespread in the Earth's crust and in living organisms but is relatively scarce

title: Phosphorus

text: phosphides, which are generally hard refractory compounds with a metallic lustre, and phosphorus-rich phosphides which are less stable and include semiconductors. Schreibersite 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) and its organic derivatives (PR) are structural analogues of ammonia (NH), but the bond angles at phosphorus are closer to 90° for phosphine and its organic derivatives. It is an ill-smelling, toxic compound. Phosphorus has an oxidation number of -3 in phosphine. Phosphine is produced by hydrolysis of calcium phosphide, CaP. Unlike ammonia, phosphine is oxidised

title: Doctor Phosphorus

text: his wife Francine for information about Langstrom's research. However, Phosphorus caused Kirk to transform into Man-Bat and throw Phosphorus into the ocean. During the "Brightest Day" crossover event, Phosphorus is freed from Arkham when Deathstroke and the attack the facility. However, before Phosphorus can escape, he is attacked by Arsenal. In September 2011, The New 52 rebooted DC's continuity. In this new timeline, Doctor Phosphorus is reintroduced in the "Forever Evil" storyline, appearing among the villains that the Crime Syndicate of America recruits to join the Secret Society of Super Villains. Doctor Phosphorus has burning skin, toxic emissions, and can

title: Phosphorus

text: the phosphorus can be in P(V), P(III) or other oxidation states. The most famous is the three-fold symmetric PS which is used in strike-anywhere matches. PS and PO 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 serves as 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

title: Phosphorus Rex

text: Phosphorus Rex Phosphorus Rex is a supervillain in DC Comics. Phosphorus Rex first appeared in "Batman" #666 and was created by Grant Morrison. Phosphorus Rex is a fiery member of the Circus of Strange. After Mister Toad was apprehended by the Gotham City Police Department, Phosphorus Rex joined the Circus of Strange members Big Top, Siam, and a group of Professor Pyg's Dollotrons into attacking the Gotham City Police Department which resulted in four police officers getting killed and six others ending up injured. Phosphorus Rex and the rest of the Circus of Strange were defeated by Batman and Robin.

title: Phosphorus-32

text: substrate can then be traced by detecting which molecules contain the phosphorus-32 at multiple time points following the initial treatment. DNA contains a large quantity of phosphorus in the phosphodiester linkages between bases in the oligonucleotide chain. DNA can therefore be tracked by replacing the phosphorus with phosphorus-32. This technique is extensively used in Southern blot analysis of DNA samples. In this case a phosphorus-32-containing DNA probe hybridises to its complementary sequence where it appears in a gel. Its location can then be detected by photographic film. Phosphorus-32 is used in plant sciences for tracking a plant's uptake of fertiliser

title: Phosphorus tribromide

text: Phosphorus tribromide Phosphorus tribromide is a colourless liquid with the formula PBr. It is a colourless liquid that fumes in moist air due to hydrolysis and has a penetrating odour. It is used in the laboratory for the conversion of alcohols to alkyl bromides. PBr is prepared by treating red phosphorus with bromine. An excess of phosphorus is used in order to prevent formation of PBr: Because the reaction is highly exothermic, it is often conducted in the presence of a diluent such as PBr. Phosphorus tribromide, like PCl and PF, has both properties of a Lewis base and a

title: Phosphorus trioxide

text: Phosphorus trioxide Phosphorus trioxide is the chemical compound with the molecular formula PO. Although it should properly be named tetraphosphorus hexoxide, the name phosphorus trioxide preceded the knowledge of the compound's molecular structure, and its usage continues today. This colorless solid is structurally related to adamantane. It is formally the anhydride of phosphorous acid, HPO, but cannot be obtained by the dehydration of the acid. It is a white, waxy, crystalline and highly toxic solid with garlic odour. It is obtained by the combustion of phosphorus in a limited supply of air at low temperature. By-products include red phosphorus suboxide.

title: Phosphorus trichloride

text: is consistent with this description. PCl is a precursor to other phosphorus compounds, undergoing oxidation to phosphorus pentachloride (PCl), thiophosphoryl chloride (PSCl), or phosphorus oxychloride (POCl). If an electric discharge is passed through a mixture of PCl vapour and hydrogen gas, a rare chloride of phosphorus is formed, diphosphorus tetrachloride (PCl). Phosphorus trichloride is the precursor to organophosphorus compounds that contain one or more P(III) atoms, most notably phosphites and phosphonates. These compounds do not usually contain the chlorine atoms found in PCl. PCl reacts vigorously with water to form phosphorous acid, HPO and HCl: A large number of similar

title: Phosphorus

text: was introduced to reduce phosphate rock. The electric furnace method allowed production to increase to the point where phosphorus could be used in weapons of war. In World War I, it was used in incendiaries, smoke screens and tracer bullets. A special incendiary bullet was developed to shoot at hydrogen-filled Zeppelins over Britain (hydrogen being highly flammable). During World War II, Molotov cocktails made of phosphorus dissolved in petrol were distributed in Britain to specially selected civilians within the British resistance operation, for defence; and phosphorus incendiary bombs were used in war on a large scale. Burning phosphorus is difficult

title: Phosphorus sulfide

text: order of the discovery of the isomers, not their structure. All known molecular phosphorus sulfides contain a tetrahedral array of four phosphorus atoms. PS is also known but is unstable above −30 °C. The main method for preparing these compounds is thermolysis of mixtures of phosphorus and sulfur. The product distributions can be analyzed by P NMR spectroscopy. More selective syntheses entail (i) desulfurization, e.g. using triphenylphosphine and, complementarily, (ii) sulfidation using triphenylarsine sulfide. Phosphorus sesquisulfide is prepared by treating red phosphorus with sulfur above 450 K, followed by careful recrystallization with carbon disulfide and benzene. An alternative method involves

title: Phosphorus pentabromide

text: is susceptible to further addition to yield phosphorus heptabromide (PBr). Phosphorus pentabromide Phosphorus pentabromide is a reactive, yellow solid of formula PBr, which has the structure PBr Br in the solid state but in the vapor phase is completely dissociated to PBr and Br. Rapid cooling of this phase to 15 K leads to formation of the ionic species phosphorus heptabromide ([PBr][Br]). It can be used in organic chemistry to convert carboxylic acids to acyl bromides. It is highly corrosive. It decomposes above 100 °C to give phosphorus tribromide and bromine: Reversing this equilibrium to generate PBr by addition of

title: Phosphorus trichloride

text: Phosphorus trichloride Phosphorus trichloride is a chemical compound of phosphorus and chlorine, having the chemical formula PCl. It has a trigonal pyramidal shape. It is the most important of the three phosphorus chlorides. It is an important industrial chemical, being used for the manufacture of organophosphorus compounds for a wide variety of applications. It has a P NMR signal at around +220 ppm with reference to a phosphoric acid standard. The phosphorus in PCl is often considered to have the +3 oxidation state and the chlorine atoms are considered to be in the −1 oxidation state. Most of its reactivity

title: Phosphorus acid

text: Phosphorus acid Phosphorus oxoacids are oxoacids of phosphorus. Phosphorus exhibits oxidation states from +1 to +5. Oxygen may be in oxidation state -2 or -1, depending on whether a compound contains the peroxide group. There are a large number of such compounds, some of which cannot be isolated and are only known through their salts. Examples of phosphorus acids include: Phosphorus oxoacids containing P in oxidation state +1: Phosphorus oxoacids containing P in oxidation state +3: Phosphorus oxoacids containing P in oxidation state +5 (see also phosphoric acids and phosphates): Phosphorus oxoacids containing P in oxidation state +4: Phosphorus oxoacids

title: Phosphorus selenide

text: Phosphorus selenide Phosphorus selenides are a relatively obscure group of compounds. There have been some studies of the phosphorus - selenium phase diagram and the glassy amorphous phases are reported. The compounds that have been reported are shown below. While some are similar to their phosphorus analogues, the phosphorus sulfides, there are some new forms, molecular PSe and the polymeric "catena"-[PSe]. There is also some doubt about the existence of molecular PSe. Molecular PSe has a norbornane like structure with two phosphorus atoms with oxidation state +3 bridged by two diselenide units, (-Se-Se-), (analogous to disulfide) and one selenide unit(-Se-).

title: Phosphorus cycle

text: the later stage of weathering and soil development. Available phosphorus is found in a biogeochemical cycle in the upper soil profile, while phosphorus found at lower depths is primarily involved in geochemical reactions with secondary minerals. Plant growth depends on the rapid root uptake of phosphorus released from dead organic matter in the biochemical cycle. Phosphorus is limited in supply for plant growth. Phosphates move quickly through plants and animals; however, the processes that move them through the soil or ocean are very slow, making the phosphorus cycle overall one of the slowest biogeochemical cycles. Low-molecular-weight (LMW) organic acids are

title: Doctor Phosphorus

text: manipulate radiation. When he sells his soul to Neron, he is granted better control of his powers so that any clothes that he wears will not burn off. In the alternate timeline of the "Flashpoint" event, Doctor Phosphorus was invited by Lt. Matthew Shrieve to be the new member of Creature Commandos, but Doctor Phosphorus then betrays him and kills his family. It is revealed that Doctor Phosphorus had been working for General Sam Lane who is responsible for the deaths of Miranda's family. Doctor Phosphorus appears in "The Lego Batman Movie". Doctor Phosphorus appears in Smallville Season 11: Titans.

title: Phosphorus deficiency

text: phosphorus levels before discoloration occurs. The most prominent method of checking phosphorus levels is by soil testing. The major soil testing methods are Bray 1-P, Mehlich 3, and Olsen methods. Each of these methods are viable but each method has tendencies to be more accurate in known geographical areas. These tests use chemical solutions to extract phosphorus from the soil. The extract must then be analyzed to determine the concentration of the phosphorus. Colorimetry is used to determine this concentration. With the addition of the phosphorus extract into a colorimeter, there is visual color change of the solution and the

title: Peak phosphorus

text: phosphorus nowadays is phosphate rock. According to some researchers, Earth's commercial and affordable phosphorus reserves are expected to be depleted in 50–100 years and peak phosphorus to be reached in approximately 2030. Others suggest that supplies will last for several hundreds of years. As with the timing of peak oil, the question is not settled, and researchers in different fields regularly publish different estimates of the rock phosphate reserves. The peak phosphorus concept is connected with the concept of planetary boundaries. Phosphorus, as part of biogeochemical processes, belongs to one of the nine "Earth system processes" which are known to

title: Phosphorus trichloride

text: is exploited in the Kinnear–Perren reaction to prepare alkylphosphonyl dichlorides (RP(O)Cl) and alkylphosphonate esters (RP(O)(OR')). Alkylation of phosphorus trichloride is effected in the presence of aluminium trichloride give the alkyltrichlorophosphonium salts, which are versatile intermediates: The RPCl product can then be decomposed with water to produce an alkylphosphonic dichloride RP(=O)Cl. World production exceeds one-third of a million tonnes. Phosphorus trichloride is prepared industrially by the reaction of chlorine with a refluxing solution of white phosphorus in phosphorus trichloride, with continuous removal of PCl as it is formed (in order to avoid the formation of PCl). Industrial production of phosphorus trichloride

title: Allotropes of phosphorus

text: weapon. Although white phosphorus converts to the thermodynamically more stable red allotrope, the formation of the cubic P molecule is not observed in the condensed phase. Analogs of this hypothetical molecule have been prepared from phosphaalkynes. Red phosphorus may be formed by heating white phosphorus to in the absence of air or by exposing white phosphorus to sunlight. Red phosphorus exists as an amorphous network. Upon further heating, the amorphous red phosphorus crystallizes. Red phosphorus does not ignite in air at temperatures below , whereas pieces of white phosphorus ignite at about . Ignition is spontaneous at room temperature with

title: Phosphorus pentafluoride

text: structures are, relative to a molecule in solution, static and can not undergo the necessary changes in atomic position. Phosphorus pentafluoride Phosphorus pentafluoride, PF, is a phosphorus halide. It is a colourless, toxic gas that fumes in air. Phosphorus pentafluoride was first prepared in 1876 by the fluorination of phosphorus pentachloride using arsenic trifluoride, which remains a favored method: Single-crystal X-ray studies indicate that the PF has trigonal bipyramidal geometry. Thus it has two distinct types of P−F bonds (axial and equatorial): the length of an axial P−F bond is distinct from the equatorial P-F bond in the solid phase,

title: Phosphorus pentafluoride

text: Phosphorus pentafluoride Phosphorus pentafluoride, PF, is a phosphorus halide. It is a colourless, toxic gas that fumes in air. Phosphorus pentafluoride was first prepared in 1876 by the fluorination of phosphorus pentachloride using arsenic trifluoride, which remains a favored method: Single-crystal X-ray studies indicate that the PF has trigonal bipyramidal geometry. Thus it has two distinct types of P−F bonds (axial and equatorial): the length of an axial P−F bond is distinct from the equatorial P-F bond in the solid phase, but not the liquid or gas phases due to Pseudo Berry Rotation. Fluorine-19 NMR spectroscopy, even at temperatures as

title: Phosphorus-32

text: possible chemotherapy agent to treat disseminated ovarian cancer. In this situation it is the longterm toxic effects of beta radiation from phosphorus-32 accumulating in the cancerous cells which has the therapeutic effect.The Phosphorus-32 is widely used radioisotope for cancer detection and treatment, especially in eyes and skin cancer. The metabolic pathways of organisms extensively use phosphorus in the generation of different biomolecules within the cell. Phosphorus-32 finds use for analysing metabolic pathways in pulse chase experiments where a culture of cells is treated for a short time with a phosphorus-32-containing substrate. The sequence of chemical changes which happen to the

title: Phosphorus-32

text: the phosphorus-32 is sufficiently penetrating to be detected outside the organism or tissue which is being analysed Many radioisotopes are used as tracers in nuclear medicine, including iodine-131, phosphorus-32, and technetium-99m. Phosphorus-32 is of particular use in the identification of malignant tumours because cancerous cells have a tendency to accumulate more phosphate than normal cells. The location of the phosphorus-32 can be traced from outside the body to identify the location of potentially malignant tumors. The radiation emitted by phosphorus-32 can be used for therapeutic as well as diagnostic purposes. The use of 32P-chromic phosphate has been explored as a

title: Phosphorus acid

text: containing P in mixed oxidation states: Phosphorus acid Phosphorus oxoacids are oxoacids of phosphorus. Phosphorus exhibits oxidation states from +1 to +5. Oxygen may be in oxidation state -2 or -1, depending on whether a compound contains the peroxide group. There are a large number of such compounds, some of which cannot be isolated and are only known through their salts. Examples of phosphorus acids include: Phosphorus oxoacids containing P in oxidation state +1: Phosphorus oxoacids containing P in oxidation state +3: Phosphorus oxoacids containing P in oxidation state +5 (see also phosphoric acids and phosphates): Phosphorus oxoacids containing P

title: Phosphorus halide

text: Phosphorus halide There are three series of binary phosphorus halides, containing phosphorus in the oxidation states +5, +3 and +2. All compounds have been described, in varying degrees of detail, although serious doubts have been cast on the existence of PI. Mixed chalcogen halides also exist. In the gas phase the phosphorus pentahalides have trigonal bipyramidal molecular geometry as explained by VSEPR theory. Phosphorus pentafluoride is a relatively inert gas, notable as a mild Lewis acid and a fluoride ion acceptor. It is a fluxional molecule in which the axial (ax) and equatorial (eq) fluorine atoms interchange positions by the

title: Phosphorus selenide

text: with P=Se double bond) and P units (P in formal oxidation state +4). There is no evidence for an amorphous phase containing molecular PSe. Phosphorus selenide Phosphorus selenides are a relatively obscure group of compounds. There have been some studies of the phosphorus - selenium phase diagram and the glassy amorphous phases are reported. The compounds that have been reported are shown below. While some are similar to their phosphorus analogues, the phosphorus sulfides, there are some new forms, molecular PSe and the polymeric "catena"-[PSe]. There is also some doubt about the existence of molecular PSe. Molecular PSe has a

title: Peak phosphorus

text: recovery methods from sewage sludge has been carried out in Sweden and Germany since around 2003, but the technologies currently under development are not yet cost effective, given the current price of phosphorus on the world market. Peak phosphorus Peak phosphorus is a concept to describe the point in time when humanity reaches the maximum global production rate of phosphorus as an industrial and commercial raw material. The term is used in an equivalent way to the better-known term peak oil. The issue was raised as a debate on whether a "peak phosphorus" was imminent or not around 2010, but

title: Phosphorus-32

text: from the roots to the leaves. The phosphorus-32-labelled fertiliser is given to the plant hydroponically or via water in the soil and the usage of the phosphorus can be mapped from the emitted beta radiation. The information gathered by mapping the fertiliser uptake show how the plant takes up and uses the phosphorus from fertiliser. The high energy of emitted beta particles and the low half-life of phosphorus-32 make it potentially harmful; its maximum specific activity is 338 TBq/mmol (9131 Ci/mmol). Typical safety precautions when working with phosphorus-32 include wearing a personal dosimeter to monitor exposure and an acrylic or

title: Phosphorus

text: 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 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). Twenty-three isotopes of phosphorus are known, including all possibilities from up to . Only is stable and is therefore present at 100% abundance. The half-integer nuclear spin and

title: Peak phosphorus

text: that have an enhanced biological phosphorus removal step produce a sewage sludge that is rich in phosphorus. Various processes have been developed to extract phosphorus from sewage sludge directly, from the ash after incineration of the sewage sludge or from other products of sewage sludge treatment. This includes the extraction of phosphorus rich materials such as struvite from waste processing plants. The struvite can be made by adding magnesium to the waste. Some companies such as Ostara in Canada and NuReSys in Belgium are already using this technique to recover phosphate. Ostara has eight operating plants worldwide. Research on phosphorus

title: Phosphorus

text: phosphorus, which may be produced by reaction and distillation from very low grade phosphate sources. The white phosphorus is then oxidised to phosphoric acid and subsequently neutralised with base to give phosphate salts. Phosphoric acid produced from white phosphorus is relatively pure and is the main route for the production of phosphates for all purposes, including detergent production. In the early 1990s, Albright and Wilson's purified wet phosphoric acid business was being adversely affected by phosphate rock sales by China and the entry of their long-standing Moroccan phosphate suppliers into the purified wet phosphoric acid business. In 2017, the USGS

title: Phosphorus trioxide

text: the toluene solution at 244K, PO(BH) rather than an adduct of PO is formed: Phosphorus trioxide Phosphorus trioxide is the chemical compound with the molecular formula PO. Although it should properly be named tetraphosphorus hexoxide, the name phosphorus trioxide preceded the knowledge of the compound's molecular structure, and its usage continues today. This colorless solid is structurally related to adamantane. It is formally the anhydride of phosphorous acid, HPO, but cannot be obtained by the dehydration of the acid. It is a white, waxy, crystalline and highly toxic solid with garlic odour. It is obtained by the combustion of phosphorus

title: Allotropes of phosphorus

text: relative molecular mass, which on heating breaks down into P molecules. On cooling, these would normally dimerize to give P molecules (i.e. white phosphorus) but, in vacuo, they link up again to form the polymeric violet allotrope. Black phosphorus is the thermodynamically stable form of phosphorus at room temperature and pressure, with a heat of formation of -39.3 kJ/mol (relative to white phosphorus which is defined as the standard state). It is obtained by heating white phosphorus under high pressures (12,000 atmospheres). In appearance, properties, and structure, black phosphorus is very much like graphite with both being black and flaky,

title: Phosphorus

text: 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, the yellowish liquids PCl and PBr, and the solid PI. 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 is toxic because it binds to haemoglobin. Phosphorus(III) oxide, PO (also called tetraphosphorus hexoxide) is the anhydride of P(OH), the minor tautomer of phosphorous

title: Phosphorus pentabromide

text: Phosphorus pentabromide Phosphorus pentabromide is a reactive, yellow solid of formula PBr, which has the structure PBr Br in the solid state but in the vapor phase is completely dissociated to PBr and Br. Rapid cooling of this phase to 15 K leads to formation of the ionic species phosphorus heptabromide ([PBr][Br]). It can be used in organic chemistry to convert carboxylic acids to acyl bromides. It is highly corrosive. It decomposes above 100 °C to give phosphorus tribromide and bromine: Reversing this equilibrium to generate PBr by addition of Br to PBr is difficult in practice because the product

title: Phosphorus pentachloride

text: the French chemist Pierre Louis Dulong. Phosphorus pentachloride Phosphorus pentachloride is the chemical compound with the formula PCl. It is one of the most important phosphorus chlorides, others being PCl and POCl. PCl finds use as a chlorinating reagent. It is a colourless, water-sensitive and moisture-sensitive solid, although commercial samples can be yellowish and contaminated with hydrogen chloride. The structures for the phosphorus chlorides are invariably consistent with VSEPR theory. The structure of PCl depends on its environment. Gaseous and molten PCl is a neutral molecule with trigonal bipyramidal geometry and ("D") symmetry. The hypervalent nature of this species (as

title: Phosphorus pentachloride

text: Phosphorus pentachloride Phosphorus pentachloride is the chemical compound with the formula PCl. It is one of the most important phosphorus chlorides, others being PCl and POCl. PCl finds use as a chlorinating reagent. It is a colourless, water-sensitive and moisture-sensitive solid, although commercial samples can be yellowish and contaminated with hydrogen chloride. The structures for the phosphorus chlorides are invariably consistent with VSEPR theory. The structure of PCl depends on its environment. Gaseous and molten PCl is a neutral molecule with trigonal bipyramidal geometry and ("D") symmetry. The hypervalent nature of this species (as well as for , see below)

title: Phosphorus

text: strikes them, or by their phosphorescence in the dark. In dark surroundings, fragments are seen as luminescent spots. Promptly debride the burn if the patient's condition will permit removal of bits of WP (white phosphorus) that 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. People can

title: Phosphorus cycle

text: from resilient to more labile forms. This could eventually increase the potential for phosphorus loss. This is of particular concern for the environmentally sound management of such areas, where disposal of agricultural wastes has already become a problem. It is suggested that the water regime of soils that are to be used for organic wastes disposal is taken into account in the preparation of waste management regulations. Human interference in the phosphorus cycle occurs by overuse or careless use of phosphorus fertilizers. This results in increased amounts of phosphorus as pollutants in bodies of water resulting in eutrophication. Eutrophication devastates

title: Phosphorus sesquisulfide

text: contains public domain text from the NOAA as cited." Phosphorus sesquisulfide Phosphorus sesquisulfide is the inorganic compound with the formula . It was developed by Henri Sevene and Emile David Cahen in 1898 as part of their invention of friction matches that did not pose the health hazards of white phosphorus. This yellow solid is one of two commercially produced phosphorus sulfides. It is a component of "strike anywhere" matches. Depending on purity, samples can appear yellow-green to grey. The compound was discovered by G. Lemoine and first produced safely in commercial quantities in 1898 by Albright and Wilson. It

title: Phosphorus sesquisulfide

text: Phosphorus sesquisulfide Phosphorus sesquisulfide is the inorganic compound with the formula . It was developed by Henri Sevene and Emile David Cahen in 1898 as part of their invention of friction matches that did not pose the health hazards of white phosphorus. This yellow solid is one of two commercially produced phosphorus sulfides. It is a component of "strike anywhere" matches. Depending on purity, samples can appear yellow-green to grey. The compound was discovered by G. Lemoine and first produced safely in commercial quantities in 1898 by Albright and Wilson. It dissolves in an equal weight of carbon disulfide (CS).

title: Parides phosphorus

text: provided by Rothschild, W. and Jordan, K. (1906) "Parides phosphorus" is a member of the "anchises" species group The members are Parides phosphorus Parides phosphorus is a species of butterfly in the family Papilionidae. It is found in the Neotropical ecozone. The larvae feed on "Aristolochia". P. phosphorus. Palpi red. Forewing somewhat transparent distally; male with dirty-green spot; hindwing rather strongly dentate, the red spots remote from the cell. Tibiae armed with spines, not thickened.Female with grey-green area on the forewing before the hindmargin, which occurs in no other female of the Aristolochia- Papilios. Colombia; Guiana; Lower Amazon; East Peru;

title: Phosphorus deficiency

text: a result of this process can turn leaves a dark purplish color. Detecting phosphorus deficiency can take multiple forms. A preliminary detection method is a visual inspection of plants. Darker green leaves and purplish or red pigment can indicate a deficiency in phosphorus. This method however can be an unclear diagnosis because other plant environment factors can result in similar discoloration symptoms. In commercial or well monitored settings for plants, phosphorus deficiency is diagnosed by scientific testing. Additionally, discoloration in plant leaves only occurs under fairly severe phosphorus deficiency so it is beneficial to planters and farmers to scientifically check

title: Peak phosphorus

text: recycling phosphorus is through the reuse of animal manure and human excreta in agriculture. Via this method, phosphorus in the foods consumed are excreted, and the animal or human excreta are subsequently collected and re-applied to the fields. Although this method has maintained civilizations for centuries the current system of manure management is not logistically geared towards application to crop fields on a large scale. At present, manure application could not meet the phosphorus needs of large scale agriculture. Despite that, it is still an efficient method of recycling used phosphorus and returning it to the soil. Sewage treatment plants

title: Phosphorus trifluoride

text: Phosphorus trifluoride Phosphorus trifluoride (formula PF), is a colorless and odorless gas. It is highly toxic and reacts slowly with water. Its main use is as a ligand in metal complexes. As a ligand, it parallels carbon monoxide in metal carbonyls, and indeed its toxicity is due to its binding with the iron in blood hemoglobin in a similar way to carbon monoxide. Phosphorus trifluoride has an F−P−F bond angle of approximately 96.3°. Gaseous PF has a standard enthalpy of formation of −945 kJ/mol (−226 kcal/mol). The phosphorus atom has a nuclear magnetic resonance chemical shift of 97 ppm (downfield

title: Doctor Phosphorus

text: a second time; this time, Phosphorus has given Knight a significant dose of radiation, which gave him terminal cancer. In a third and final confrontation, Knight is determined to ensure that Phosphorus would harm no one else. During the battle, he uses his cosmic rod to tear the pavement from beneath Phosphorus and drive him into the earth, apparently killing him. Phosphorus returns in "Detective Comics" #825, where he is being held in Cadmus Research laboratories. When one of the scientists examining him says he heard Sartorius had died, the other replies, "From being crushed? Hardly. Everything human in Sartorius

title: Phosphorus pentoxide

text: glass or amorphous form; it can be made by fusing any of the others. PO is prepared by burning tetraphosphorus with sufficient supply of oxygen: For most of the 20th century, phosphorus pentoxide was used to provide a supply of concentrated pure phosphoric acid. In the thermal process, the phosphorus pentoxide obtained by burning white phosphorus was dissolved in dilute phosphoric acid to produce concentrated acid. Improvements in filter technology is leading to the "wet phosphoric acid process" taking over from the thermal process, obviating the need to produce white phosphorus as a starting material. The dehydration of phosphoric acid

title: Phosphorus halide

text: starting material for phosphorus chemistry. Phosphorus tribromide is used in organic chemistry to convert alcohols to alkyl bromides and carboxylic acids to acyl bromides ("e.g." in the Hell-Volhard-Zelinsky reaction). Phosphorus triiodide also finds use in organic chemistry, as a mild oxygen acceptor. The trihalides are fairly readily oxidized by chalcogens to give the corresponding oxyhalides or equivalents. Phosphorus(II) halides may be prepared by passing an electric discharge through a mixture of the trihalide vapour and hydrogen gas. The relatively stable PI is known to have a "trans", bent configuration similar to hydrazine and finds some uses in organic syntheses, the