Phosphorus is a chemical element with the symbol P and atomic number 15. It exists in two major forms, white and Red phosphorus, but because it is highly reactive, It 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). In minerals, phosphorus generally occurs as phosphate. that at room temperature is a colourless, semitransparent, soft, waxy solid that glows in the dark. Elemental phosphorus was first isolated as white phosphorus in 1669.
White P emits a faint glow when exposed to oxygen, hence the name taken from Greek word which meaning “light-bearer” referring to the “Morning Star”, the planet Venus. The term “phosphorescence” meaning glow after illumination, derives from this property of P, although the word has since been used for a diverse physical process that produces a glow. The glow of P is caused by oxidation of the white phosphorus.
It is a very widely distributed element—12th most abundant in crust Earth’s , to which it contributes about 0.10 weight percent. Its cosmic abundance is about one atom per 100 atoms of silicon, the standard. Its high chemical reactivity assures that it does not occur in the free state. It always occurs as the phosphate ion. The principal combined forms in nature are the phosphate salts. About 550 different minerals have been found to contain phosphorus, but, of these, the principal source of phosphorus is the apatite series in which calcium ions exist along with phosphate ions and variable amounts of fluoride, chloride, or hydroxide ions, according to the formula [Ca10(PO4)6(F, Cl, or OH)2].
Commercial Uses of Phosphate
The principal technique for converting phosphate rock to usable materials involves acidulation of the crushed rock—with either sulfuric or phosphoric acids—to form crude calcium hydrogen phosphates that, being water-soluble, are valuable additions to fertilizer. Most of the output is burned to phosphoric anhydride and subsequently treated with water to form phosphoric acid, H3PO4. About 95% of the phosphate rock mined in the United States is used to make fertilizer or food supplements for animals. Concerns have arisen about phosphorus use, however. Most of the phosphorus is wasted on its journey from mining to being eaten by humans, and the wasted phosphorus ends up in waterways where it can cause algal blooms. Another concern is that increased phosphorus usage will deplete the nonrenewable supply of phosphate rock.
Biological role of Phosphorus
In medicine, phosphate deficiency syndrome may be caused by malnutrition, by failure to absorb phosphate, and by metabolic syndromes that draw phosphate from the blood or pass too much of it into the urine. All are characterised by hypophosphatemia, which is a condition of low levels of soluble phosphate levels in the blood serum and inside the cells. Symptoms of hypophosphatemia include neurological dysfunction and disruption of muscle and blood cells due to lack of ATP. Too much phosphate can lead to diarrhoea and calcification (hardening) of organs and soft tissue, and can interfere with the body’s ability to use iron, calcium, magnesium, and zinc.
It is an essential macro mineral for plants, which is studied extensively in edaphology to understand 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.