Reactive nonmetal
Phosphorus is a chemical element; it has symbol P and atomic number 15. All elemental forms of phosphorus are highly reactive and are therefore never found in nature. Elemental phosphorus can be prepared artificially, the two most common allotropes being white phosphorus and red phosphorus. With 31P as its only stable isotope, phosphorus has an occurrence in Earth's crust of about 0.1%, generally as phosphate rock. A member of the pnictogen family, phosphorus readily forms a wide variety of organic and inorganic compounds, with as its main oxidation states +5, +3 and −3.
The isolation of white phosphorus in 1669 by Hennig Brand marked the scientific community's first discovery of an element since antiquity. The name phosphorus is a reference to the god of the Morning star in Greek mythology, inspired by the faint glow of white phosphorus when exposed to oxygen. This property is also at the origin of the term phosphorescence, meaning glow after illumination, although white phosphorus itself does not exhibit phosphorescence, but chemiluminescence caused by its oxidation. Its high toxicity makes exposure to white phosphorus very dangerous, while its flammability and pyrophoricity can be weaponised in the form of incendiaries. Red phosphorus is less dangerous and is used in matches and fire retardants.
Most industrial production of phosphorus is focused on the mining and transformation of phosphate rock into phosphoric acid for phosphate-based fertilisers. …
Phosphorus was the first element to be "discovered", in the sense that it was not known since ancient times. The discovery is credited to the Hamburg alchemist Hennig Brand in 1669, who was attempting to create the fabled philosopher's stone. To this end, he experimented with urine, which contains considerable quantities of dissolved phosphates from normal metabolism. By letting the urine rot (a step later discovered to be unnecessary), boiling it down to a paste, then distilling it at a high temperature and leading the resulting vapours through water, he obtained a white, waxy substance that glowed in the dark and burned brilliantly. He named it in Latin: phosphorus mirabilis, lit. 'miraculous bearer of light'. The word phosphorus itself (Ancient Greek: Φωσφόρος, romanized: Phōsphoros, lit. 'light-bearer') originates from Greek mythology, where it references the god of the morning star, also known as the planet Venus.
Brand at first tried to keep the method secret, but later sold the recipe for 200 thalers to Johann Daniel Kraft from Dresden. Kraft toured much of Europe with it, including London, where he met with Robert Boyle. The crucial fact that the substance was made from urine was eventually found out, and Johann Kunckel was able to reproduce it in Sweden in 1678. In 1680, Boyle also managed to make phosphorus and published the method of its manufacture. …
There are 22 known isotopes of phosphorus, ranging from 26P to 47P. Only 31P is stable and, therefore, has 100% abundance. The nuclear spin of 1/2 and high abundance of 31P make phosphorus-31 nuclear magnetic resonance spectroscopy a very useful analytical tool in studies of phosphorus-containing samples.
Two radioactive isotopes of phosphorus have half-lives suitable for biological scientific experiments, and are used as radioactive tracers in biochemical laboratories. These are:
32P, a beta-emitter (1.71 MeV) with a half-life of 14.3 days, which is used routinely in life-science laboratories, primarily to produce radiolabeled DNA and RNA probes, e.g. for use in Northern blots or Southern blots.
33P, a beta-emitter (0.25 MeV) with a half-life of 25.4 days. It is used in life-science laboratories in applications in which lower energy beta emissions are advantageous such as DNA sequencing.
The high-energy beta particles from 32P penetrate skin and corneas and any 32P ingested, inhaled, or absorbed is readily incorporated into bone and nucleic acids. For these reasons, anyone working with 32P must wear lab coats, disposable gloves, and safety glasses, and avoid working directly over open containers. Monitoring personal, clothing, and surface contamination is also required. The high energy of the beta particles gives rise to secondary emission of X-rays via Bremsstrahlung (braking radiation) in dense shielding materials such as lead. …
Phosphorus has a concentration in the Earth's crust of about one gram per kilogram (for comparison, copper is found at about 0.06 grams per kilogram). It is not found free in nature, but is widely distributed in many minerals, usually as phosphates. Inorganic phosphate rock, which is partially made of apatite, is today the chief commercial source of this element.
In 2013, astronomers detected phosphorus in Cassiopeia A, which confirmed that this element is produced in supernovae as a byproduct of supernova nucleosynthesis. The phosphorus-to-iron ratio in material from the supernova remnant could be up to 100 times higher than in the Milky Way in general. In 2020, astronomers analysed ALMA and ROSINA data from the massive star-forming region AFGL 5142, to detect phosphorus-bearing molecules and how they could have been carried in comets to the early Earth.
Safety matches are very difficult to ignite on any surface other than a special striker strip. The strip contains non-toxic red phosphorus and the match head potassium chlorate, an oxygen-releasing compound. When struck, small amounts of abrasion from match head and striker strip are mixed intimately to make a small quantity of Armstrong's mixture, a very touch sensitive composition. The fine powder ignites immediately and provides the initial spark to set off the match head. Safety matches separate the two components of the ignition mixture until the match is struck. This is the key safety advantage as it prevents accidental ignition.
Though military uses of white phosphorus are constrained by modern international law, white phosphorus munitions are still used for military applications, such as incendiary bombs, smoke screens, smoke bombs, and tracer ammunition.
Elemental phosphorus can reduce elemental iodine to hydroiodic acid, which is a reagent effective for reducing ephedrine or pseudoephedrine to methamphetamine. For this reason, red and white phosphorus are listed in the United States as List I precursor chemicals by the Drug Enforcement Administration, and their handling is subject to stringent regulatory controls.
Phosphorus is also an important component in steel production, in the making of phosphor bronze, and in many other related products. …
There are 22 known isotopes of phosphorus, ranging from 26P to 47P. Only 31P is stable and, therefore, has 100% abundance. The nuclear spin of 1/2 and high abundance of 31P make phosphorus-31 nuclear magnetic resonance spectroscopy a very useful analytical tool in studies of phosphorus-containing samples.
Two radioactive isotopes of phosphorus have half-lives suitable for biological scientific experiments, and are used as radioactive tracers in biochemical laboratories. These are:
32P, a beta-emitter (1.71 MeV) with a half-life of 14.3 days, which is used routinely in life-science laboratories, primarily to produce radiolabeled DNA and RNA probes, e.g. for use in Northern blots or Southern blots.
33P, a beta-emitter (0.25 MeV) with a half-life of 25.4 days. It is used in life-science laboratories in applications in which lower energy beta emissions are advantageous such as DNA sequencing.
The high-energy beta particles from 32P penetrate skin and corneas and any 32P ingested, inhaled, or absorbed is readily incorporated into bone and nucleic acids. For these reasons, anyone working with 32P must wear lab coats, disposable gloves, and safety glasses, and avoid working directly over open containers. Monitoring personal, clothing, and surface contamination is also required. The high energy of the beta particles gives rise to secondary emission of X-rays via Bremsstrahlung (braking radiation) in dense shielding materials such as lead. …
Inorganic phosphorus in the form of the phosphate PO3−4 is required for all known forms of life. Phosphorus plays a major role in the structural framework of DNA and RNA. Living cells use phosphate to transport cellular energy with adenosine triphosphate (ATP), necessary for every cellular process that uses energy. ATP is also important for phosphorylation, a key regulatory event in cells. Every living cell is encased in a membrane that separates it from its surroundings. Cellular membranes are composed of a phospholipid matrix and proteins, typically in the form of a bilayer. Phospholipids are derived from glycerol with two of the glycerol hydroxyl (OH) protons replaced by fatty acids as an ester, and the third hydroxyl proton has been replaced with phosphate bonded to another alcohol.
The main component of bone is hydroxyapatite as well as amorphous forms of calcium phosphate, possibly including carbonate. Hydroxyapatite is the main component of tooth enamel. Water fluoridation enhances the resistance of teeth to decay by the partial conversion of this mineral to the still harder material fluorapatite:
Ca5(PO4)3OH + F− → Ca5(PO4)3F + OH−
An average adult human contains about 0.7 kilograms (1.5 lb) of phosphorus, about 85–90% in bones and teeth in the form of apatite, and the remainder in soft tissues and extracellular fluids. The phosphorus content increases from about 0.5% by mass in infancy to 0.65–1.1% by mass in adults. …