Phosphorus (pronounced /ˈfɒsfərəs/, FOS-fər-əs) is the chemical element A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. The term is also used to refer to a pure chemical substance composed of atoms with the same number of protons. Common examples of elements are iron, copper, silver, gold, hydrogen, carbon, that has the symbol P and atomic number In chemistry and physics, the atomic number is the number of protons found in the nucleus of an atom and therefore identical to the charge number of the nucleus. It is conventionally represented by the symbol Z. The atomic number uniquely identifies a chemical element. In an atom of neutral charge, the atomic number is also equal to the number of 15. A multivalent In chemistry, valence, also known as valency or valency number, is a measure of the number of chemical bonds formed by the atoms of a given element. Over the last century, the concept of valence evolved into a range of approaches for describing the chemical bond, including Lewis structures , valence bond theory (1927), molecular orbitals (1928), nonmetal Nonmetal, or non-metal, is a term used in chemistry when classifying the chemical elements. On the basis of their general physical and chemical properties, every element in the periodic table can be termed either a metal or a nonmetal. of the nitrogen group The nitrogen group is a periodic table group consisting of nitrogen , phosphorus (P), arsenic (As), antimony (Sb), bismuth (Bi) and ununpentium (Uup) (unconfirmed), phosphorus is commonly found in inorganic phosphate rocks Phosphate minerals are those minerals that contain the tetrahedrally coordinated phosphate anion along with the freely substituting arsenate (AsO43-) and vanadate (VO43-). Chlorine (Cl-), fluorine (F-), and hydroxide (OH-) anions also fit into the crystal structure. Elemental phosphorus exists in two major forms – white phosphorus 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 and red 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. Although the term "phosphorescence Phosphorescence is a specific type of photoluminescence related to fluorescence. Unlike fluorescence, a phosphorescent material does not immediately re-emit the radiation it absorbs. The slower time scales of the re-emission are associated with "forbidden" energy state transitions in quantum mechanics. As these transitions occur less", meaning glow after illumination, derives from phosphorus, glow of phosphorus originates from oxidation of the white (but not red) phosphorus and should be called chemiluminescence Chemiluminescence is the emission of light with limited emission of heat (luminescence), as the result of a chemical reaction. Given reactants A and B, with an excited intermediate ◊,.
Due to its high reactivity, phosphorus is never found as a free element in nature on Earth. The first form of phosphorus to be discovered (white phosphorus, in 1669) emits a faint glow upon exposure to oxygen Oxygen (pronounced /ˈɒksɨdʒɨn/, OK-si-jin, from the Greek roots ὀξύς (acid, literally "sharp", from the taste of acids) and -γενής (-genēs) (producer, literally begetter), is the element with atomic number 8 and represented by the symbol O. It is a member of the chalcogen group on the periodic table, and is a highly – hence its name given from Greek mythology, Φωσφόρος meaning "light-bearer" (Latin Lucifer Lucifer is a Latin word , literally meaning "light-bearer", which in that language is used as a name for the dawn appearance of the planet Venus, heralding daylight. Use of the word in this sense is uncommon in English, in which "Day Star" or "Morning Star" are more common expressions), referring to the "Morning Star In Greek mythology, Hesperus (Roman equivalent: Vesper cf. "evening", "supper", "evening star", "west"), the Evening Star is the son of the dawn goddess Eos (Roman equivalent: Aurora) and brother of Eosphorus (Ηωσφόρος Eosphoros "dawn-bearer"); also Phosphorus (Φωσφόρος, Latin:", the planet Venus Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after Venus, the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows. Because Venus is an inferior planet from Earth, it never.
Phosphorus is a component of DNA Deoxyribonucleic acid ( /diːˌɒksɨˌraɪbɵ.nuːˈkleɪ.ɪk ˈæsɪd/ (help·info)) (DNA) is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses. The main role of DNA molecules is the long-term storage of information. DNA is often compared to a set of, RNA Ribonucleic acid is a biologically important type of molecule that consists of a long chain of nucleotide units. Each nucleotide consists of a nitrogenous base, a ribose sugar, and a phosphate. RNA is very similar to DNA, but differs in a few important structural details: in the cell, RNA is usually single-stranded, while DNA is usually double-, ATP Adenosine-5'-triphosphate is a multifunctional nucleotide used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism. It is produced by photophosphorylation and cellular respiration and used by enzymes and structural, and also the phospholipids Phospholipids are a class of lipids and are a major component of all cell membranes as they can form lipid bilayers. Most phospholipids contain a diglyceride, a phosphate group, and a simple organic molecule such as choline; one exception to this rule is sphingomyelin, which is derived from sphingosine instead of glycerol. The first phospholipid that form all cell membranes. It is, thus, an essential element for all living cells The cell is the functional basic unit of life. It was discovered by Robert Hooke and is the functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. Some organisms, such as most bacteria, are unicellular . Other organisms, such as humans,. The most important commercial use of phosphorus-based chemicals is the production of fertilizers Fertilizers are soil amendments applied to promote plant growth; the main nutrients present in fertilizer are nitrogen, phosphorus, and potassium and other nutrients ('micronutrients') are added in smaller amounts. Fertilizers are usually directly applied to soil, and also sprayed on leaves ('foliar feeding').
Phosphorus compounds are also widely used in explosives An explosive material, also called an explosive, is a substance that contains a great amount of stored energy that can produce an explosion, a sudden expansion of the material after initiation, usually accompanied by the production of light, heat, and pressure. An explosive charge is a measured quantity of explosive material, nerve agents Nerve agents, also referred to as nerve gases though these chemicals are liquid at room temperature, are a class of phosphorus-containing organic chemicals that disrupt the mechanism by which nerves transfer messages to organs. The disruption is caused by blocking acetylcholinesterase, an enzyme that normally relaxes the activity of acetylcholine,, friction matches A match is a consumable tool for lighting a fire in controlled circumstances. They are commonly sold by tobacconists and many other kinds of shops. Matches are usually sold in quantity, packaged in match boxes or matchbooks. A match is typically a wooden stick or stiff paper stick (in the case of matchbooks) coated at one end with a material which, fireworks Fireworks are a class of low explosive pyrotechnic devices used for aesthetic and entertainment purposes. The most common use of a firework is as part of a fireworks display. A fireworks event is a display of the effects produced by firework devices. Fireworks competitions are also regularly held at a number of places. Fireworks (devices) take, pesticides A pesticide is any substance or mixture of substances intended for preventing, destroying, repelling or mitigating any pest. A pesticide may be a chemical substance, biological agent , antimicrobial, disinfectant or device used against any pest. Pests include insects, plant pathogens, weeds, molluscs, birds, mammals, fish, nematodes (roundworms),, toothpaste Toothpaste is a paste or gel dentifrice used with a toothbrush as an accessory to clean and maintain the aesthetics and health of teeth. Toothpaste is used to promote oral hygiene: it acts as an abrasive that aids in removing the dental plaque and food from the teeth, assists in the elimination and/or masking of halitosis, and delivers active, and detergents A detergent is a material used for cleaning. The term is sometimes used to differentiate between soap and other surfactants used for cleaning.
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Physical properties
Glow from white phosphorus
In 1669, German alchemist Hennig Brand Hennig Brand (c. 1630 – c. 1710) was a merchant and alchemist in Hamburg, Germany. He discovered phosphorus around 1669 attempted to create the philosopher's stone The philosophers' stone sodhi kutta is a legendary alchemical substance, supposedly capable of turning base metals, especially lead, into gold (chrysopoeia); it was also sometimes believed to be an elixir of life, useful for rejuvenation and possibly for achieving immortality. For a long time, it was the most sought-after goal in Western alchemy, from his urine, and in the process he produced a white material that glowed in the dark.[4] The phosphorus had been produced from inorganic phosphate, which is a significant component of dissolved urine solids. White phosphorus is highly reactive and gives off a faint greenish glow upon uniting with oxygen Oxygen (pronounced /ˈɒksɨdʒɨn/, OK-si-jin, from the Greek roots ὀξύς (acid, literally "sharp", from the taste of acids) and -γενής (-genēs) (producer, literally begetter), is the element with atomic number 8 and represented by the symbol O. It is a member of the chalcogen group on the periodic table, and is a highly. The glow observed by Brand was caused by the very slow burning of the phosphorus, but as he neither saw flame nor felt any heat he did not recognize it as burning.
It was known from early times that the glow would persist for a time in a stoppered jar but then cease. Robert Boyle Robert Boyle was an Anglo-Irish natural philosopher, chemist, physicist, and inventor, also noted for his writings in theology. He is best known for Boyle's law. Although his research and personal philosophy clearly has its roots in the alchemical tradition, he is largely regarded today as the first modern chemist, and therefore one of the in the 1680s ascribed it to "debilitation" of the air; in fact, it is oxygen being consumed. By the 18th century, it was known that in pure oxygen, phosphorus does not glow at all;[5] there is only a range of partial pressure In a mixture of ideal gases, each gas has a partial pressure which is the pressure which the gas would have if it alone occupied the volume. The total pressure of a gas mixture is the sum of the partial pressures of each individual gas in the mixture at which it does. Heat can be applied to drive the reaction at higher pressures.[6]
In 1974, the glow was explained by R. J. van Zee and A. U. Khan.[7] A reaction with oxygen takes place at the surface of the solid (or liquid) phosphorus, forming the short-lived molecules HPO and P2O2 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.
Although the term phosphorescence Phosphorescence is a specific type of photoluminescence related to fluorescence. Unlike fluorescence, a phosphorescent material does not immediately re-emit the radiation it absorbs. The slower time scales of the re-emission are associated with "forbidden" energy state transitions in quantum mechanics. As these transitions occur less is derived from phosphorus, the reaction that gives phosphorus its glow is properly called chemiluminescence Chemiluminescence is the emission of light with limited emission of heat (luminescence), as the result of a chemical reaction. Given reactants A and B, with an excited intermediate ◊, (glowing due to a cold chemical reaction), not phosphorescence (re-emitting light that previously fell onto a substance and excited it).
Allotropes
Main article: 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 P4 moleculePhosphorus has several forms (allotropes Allotropy or allotropism is the property of some chemical elements to exist in two or more different forms, known as allotropes of these elements. Allotropes are different structural modifications of an element; the element's atoms are bonded together in a different manner) that have strikingly different properties.[8] The two most common allotropes are white phosphorus and red phosphorus. Red phosphorus is an intermediate phase between white and violet phosphorus. Another form, scarlet phosphorus, is obtained by allowing a solution of white phosphorus in carbon disulfide Carbon disulfide is a colorless, volatile liquid with the formula CS2. The compound is used frequently as a building block in organic chemistry as well as an industrial and chemical non-polar solvent. It has an "ether-like" odor, but commercial samples are typically contaminated with foul-smelling impurities, such as carbonyl sulfide to evaporate in sunlight. Black phosphorus is obtained by heating white phosphorus under high pressures (about 12,000 atmospheres). In appearance, properties, and structure, it resembles graphite The mineral graphite is one of the allotropes of carbon. It was named by Abraham Gottlob Werner in 1789 from the Greek γράφειν : "to draw/write", for its use in pencils, where it is commonly called lead, as distinguished from the actual metallic element lead. Unlike diamond (another carbon allotrope), graphite is an electrical, being black and flaky, a conductor of electricity, and has puckered sheets of linked atoms. Another allotrope is diphosphorus; it contains a phosphorus dimer as a structural unit and is highly reactive.[9]
P4O10 moleculeWhite phosphorus 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 has two forms, low-temperature β form and high-temperature α form. They both contain a phosphorus P4 tetrahedron as a structural unit, in which each atom is bound to the other three atoms by a single bond. This P4 tetrahedron is also present in liquid and gaseous phosphorus up to the temperature of 800 °C when it starts decomposing to P2 molecules.[10] White phosphorus is the least stable, the most reactive, more volatile, less dense The density of a material is defined as its mass per unit volume. The symbol of density is ρ . In some countries (for instance, in the United States), density is also defined as its weight per unit volume . The density of a substance is the reciprocal of its specific volume, a representation commonly used in thermodynamics, and more toxic than the other allotropes. The toxicity of white phosphorus led to its discontinued use in matches.[11] White phosphorus is thermodynamically unstable at normal condition and will gradually change to red phosphorus. This transformation, which is accelerated by light and heat, makes white phosphorus almost always contain some red phosphorus and therefore appear yellow. For this reason, it is also called yellow phosphorus. It glows greenish in the dark (when exposed to oxygen), is highly flammable Flammability is defined as how easily something will burn or ignite, causing fire or combustion. The degree of difficulty required to cause the combustion of a substance is quantified through fire testing. Internationally, a variety of test protocols exist to quantify flammability. The ratings achieved are used in building codes, insurance and pyrophoric A pyrophoric substance will ignite spontaneously; that is, its autoignition temperature is below room temperature. Examples are iron sulfide and many reactive metals including uranium, when powdered or sliced thinly. Pyrophoric materials are often water reactive as well and will ignite when they contact water or humid air. They can be handled (self-igniting) upon contact with air as well as toxic Toxicity is the degree to which a substance is able to damage an exposed organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell or an organ (organotoxicity), such as the liver (hepatotoxicity). By extension, the word may be (causing severe liver damage on ingestion). Because of pyrophoricity, white phosphorus is used as an additive in napalm Napalm is a thickening/gelling agent generally mixed with gasoline or a similar fuel for use in military operations. The term napalm is a combination of the names of its derivatives (coprecipitated aluminum salts of naphthenic, and palmitic acids). This type of napalm has long been obsolete in warfare. The odour of combustion of this form has a characteristic garlic smell, and samples are commonly coated with white "(di)phosphorus pentoxide Phosphorus pentoxide is a chemical compound with molecular formula P4O10. This white crystalline solid is the anhydride of phosphoric acid. It is a powerful desiccant", which consists of P4O10 tetrahedra with oxygen inserted between the phosphorus atoms and at their vertices. White phosphorus is insoluble in water but soluble in carbon disulfide.[12]
The white allotrope can be produced using several different methods. In one process, calcium Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth most abundant element by mass in the Earth's crust. Calcium is also the fifth most abundant dissolved ion in seawater by both molarity and mass, after sodium, chloride, phosphate, which is derived from phosphate rock, is heated in an electric or fuel-fired furnace in the presence of carbon Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. There are three naturally occurring isotopes, with 12C and 13C being stable, while 14C is radioactive, decaying with a half-life of and silica The chemical compound silicon dioxide, also known as silica , is an oxide of silicon with a chemical formula of Si .[13] Elemental phosphorus is then liberated as a vapour and can be collected under phosphoric acid Phosphoric acid, also known as orthophosphoric acid or phosphoric acid, is a mineral (inorganic) acid having the chemical formula H3P . This process is similar to the first synthesis of phosphorus from calcium phosphate in urine Urine is a sterile, liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream. These by-products are eventually expelled from the body in a process known.
Crystal structure of red phosphorusIn the red phosphorus, one of the P4 bonds is broken, and one additional bond is formed with a neighbouring tetrahedron resulting in a more chain-like structure. Red phosphorus may be formed by heating white phosphorus to 250 °C (482 °F) or by exposing white phosphorus to sunlight.[4] Phosphorus after this treatment exists as an amorphous network of atoms that reduces strain and gives greater stability; further heating results in the red phosphorus becoming crystalline. Therefore red phosphorus is not a certain allotrope, but rather an intermediate phase between the white and violet phosphorus, and most of its properties have a range of values. Red phosphorus does not catch fire in air at temperatures below 260 °C, whereas white phosphorus ignites at about 30 °C.[14]
Violet phosphorus is a thermodynamic stable form of phosphorus that can be produced by day-long temper of red phosphorus above 550 °C. In 1865, Hittorf discovered that when phosphorus was recrystallized 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).[9]
Crystal structure of black phosphorusBlack phosphorus is the least reactive allotrope and the thermodynamic stable form below 550 °C. It is also known as β-metallic phosphorus and has a structure somewhat resembling that of graphite.[15][16] High pressures are usually required to produce black phosphorus, but it can also be produced at ambient conditions using metal salts as catalysts.[17]
The diphosphorus allotrope, P2, is stable only at high temperatures. The dimeric unit contains a triple bond and is analogous to N2. The diphosphorus allotrope (P2) can be obtained normally only under extreme conditions (for example, from P4 at 1100 kelvin). Nevertheless, some advancements were obtained in generating the diatomic molecule in homogeneous solution, under normal conditions with the use by some transitional metal complexes (based on, for example, tungsten and niobium).[18]
| Form | white(α) | white(β) | violet | black |
|---|---|---|---|---|
| Symmetry | Body-centred cubic | Triclinic | Monoclinic | Orthorhombic |
| Pearson symbol | aP24 | mP84 | oS8 | |
| Space group | I43m | P1 No.2 | P2/c No.13 | Cmca No.64 |
| Density (g/cm3) | 1.828 | 1.88 | 2.36 | 2.69 |
| Bandgap (eV) | 2.1 | 1.5 | 0.34 | |
| Refractive index | 1.8244 | 2.6 | 2.4 |
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Fri, 13 Aug 2010 19:11:15 GMT+00:00
Auburn Journal By ThosPayne Israel violated international war crimes law when it used white phosphorus (WP) artillery shells on civilians in populous Gaza City. ...
Dianne Saxe
ue, 03 Aug 2010 11:25:24 GM
Everyone wins if farmers reduce . phosphorus. at the expense of sewage treatment plants: farmers make money; sewage treatment plants save money; and the Lake wins as phosphorous loads drop. Two feasibility studies, in 2000 and 2009, ...
Q. My science teacher told us to create a rap about two elements in the periodic table. My partner and I selected nitrogen and phosphorus. Unfortunately, neither of us have the slightest idea what to do. I never listen to rap, and my partner is an international student from Korea who barely speaks English. I have no idea what to do, and I really need help!!
Asked by Jonathan K - Thu Nov 6 00:05:13 2008 - - 1 Answers - 0 Comments
A. Find as much as can about phosphorus and nitrogen. Maybe each of u can "represent" one element. The main thing is rhyming and content. Give more attention to content than rhyming. I wish my chem teachers were as cool as urs.
Answered by Peaceful Warlord III - Thu Nov 6 00:16:43 2008
