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  • pentabromide
  • Phosphorus pentabromide is a reactive, yellow solid of formula PBr5, which has the structure PBr4+ Br− in the solid state but in the vapor phase is completely dissociated to PBr3 and Br2. (wikipedia.org)
  • Phosphorus pentabromide is a hypervalent molecule with a 3-center 4-electron bond. (wikipedia.org)
  • reaction
  • An excess of phosphorus is used in order to prevent formation of PBr5: 2 P + 3 Br2 → 2 PBr3 Because the reaction is highly exothermic, it is often conducted in the presence of a diluent such as PBr3. (wikipedia.org)
  • PBr3
  • PBr3 + 3 ROH → 3 RBr + HP(O)(OH)2 The mechanism (shown for a primary alcohol) involves formation of a phosphorus ester (to form a good leaving group), followed by an SN2 substitution. (wikipedia.org)
  • biosphere
  • Of all the elements recycled in the biosphere , phosphorus is the scarcest and therefore the one most limiting in any given ecological system. (britannica.com)
  • Phosphorus forms parts of important life-sustaining molecules that are very common in the biosphere. (wikipedia.org)
  • soils
  • Because of the steady diversion of phosphorus into the oceans, the element must be added (in fertilizers) to soils to maintain fertility and agricultural productivity. (britannica.com)
  • Low concentration of phosphorus in soils reduces plant growth, and slows soil microbial growth - as shown in studies of soil microbial biomass. (wikipedia.org)
  • Biochemistry
  • 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. (wikipedia.org)
  • Phosphorus-32 has important uses in medicine, biochemistry and molecular biology. (wikipedia.org)
  • finite
  • Phosphorus is a finite (limited) resource that is widespread in the Earth's crust and in living organisms but is relatively scarce in concentrated forms, which are not evenly distributed across the Earth. (wikipedia.org)
  • citation needed
  • Its flash point is about 100 °C.[citation needed] Exposure to "strike anywhere" matches containing phosphorus sesquisulfide can cause contact dermatitis, usually in the pocket area but also on the face. (wikipedia.org)
  • citation needed] The availability of phosphorus in an ecosystem is restricted by the rate of release of this element during weathering. (wikipedia.org)
  • toxic
  • At the same time, inefficient use of phosphorus from mine to field to fork is polluting our rivers and oceans, causing toxic algal blooms. (phosphorusfutures.net)
  • In the laboratory it may be more convenient to use the less toxic red phosphorus. (wikipedia.org)
  • 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. (wikipedia.org)
  • sufficiently
  • The beta radiation emitted by 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. (wikipedia.org)
  • abundant
  • Phosphorus is abundant in biological systems and, as a radioactive isotope is almost chemically identical with stable isotopes of the same element, phosphorus-32 can be used to label biological molecules. (wikipedia.org)