The percentage of a commodity which is recycled. The number of atoms of the element per 1 million atoms of the Earth’s crust. This is calculated by combining the scores for crustal abundance, reserve distribution, production concentration, substitutability, recycling rate and political stability scores. The Chemical Abstracts Service registry number is a unique identifier of a particular chemical, designed to prevent confusion arising from different languages and naming systems.ĭata for this section been provided by the British Geological Survey.Īn integrated supply risk index from 1 (very low risk) to 10 (very high risk). Where more than one isotope exists, the value given is the abundance weighted average.Ītoms of the same element with different numbers of neutrons. This is approximately the sum of the number of protons and neutrons in the nucleus. The mass of an atom relative to that of carbon-12. The transition of a substance directly from the solid to the gas phase without passing through a liquid phase.ĭensity is the mass of a substance that would fill 1 cm 3 at room temperature. The temperature at which the liquid–gas phase change occurs. The temperature at which the solid–liquid phase change occurs. The arrangements of electrons above the last (closed shell) noble gas. These blocks are named for the characteristic spectra they produce: sharp (s), principal (p), diffuse (d), and fundamental (f). The atomic number of each element increases by one, reading from left to right.Įlements are organised into blocks by the orbital type in which the outer electrons are found. Members of a group typically have similar properties and electron configurations in their outer shell.Ī horizontal row in the periodic table. Other applications include organophosphorus compounds in detergents, pesticides, and nerve agents.A vertical column in the periodic table. 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. The vast majority of phosphorus compounds mined are consumed as fertilisers. Low phosphate levels are an important limit to growth in a number of plant ecosystems. Phosphate mines contain fossils because phosphate is present in the fossilized deposits of animal remains and excreta. Elemental phosphorus was first isolated from human urine, and bone ash was an important early phosphate source. Phosphates are a component of DNA, RNA, ATP, and phospholipids, complex compounds fundamental to cells. Phosphorus is an element essential to sustaining life largely through phosphates, compounds containing the phosphate ion, PO43−. Phosphorus is classified as a pnictogen, together with nitrogen, arsenic, antimony, bismuth, and moscovium. The glow of phosphorus is caused by oxidation of the white (but not red) phosphorus - a process now called chemiluminescence. 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. White phosphorus emits a faint glow when exposed to oxygen – hence the name, taken from Greek mythology, Φωσφόρος meaning 'light-bearer' (Latin Lucifer), referring to the "Morning Star", the planet Venus. In white phosphorus, phosphorus atoms are arranged in groups of 4, written as P4. In minerals, phosphorus generally occurs as phosphate.Įlemental phosphorus was first isolated as white phosphorus in 1669. It has a concentration in the Earth's crust of about one gram per kilogram (compare copper at about 0. 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. Phosphorus is a chemical element with the symbol P and atomic number 15.
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