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Phosphorus is a chemical element with the symbol P and the atomic number 15. 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. It has an occurence in the Earth's crust of about 0.1%, generally occuring as phosphate in ...
A phosphoryl group is a trivalent >P(=O)− group, consisting of a phosphorus atom (symbol P) and an oxygen atom (symbol O), where the three free valencies are on the phosphorus atom. While commonly depicted as possessing a double bond (P=O) the bonding is in fact non-classical. [1]
behave as separate weak acids because the successive pK a differ by more than 4. Phosphate can form many polymeric ions such as pyrophosphate, (P 2 O 7) 4−, and triphosphate, (P 3 O 10) 5−. The various metaphosphate ions (which are usually long linear polymers) have an empirical formula of (PO 3) − and are found in many compounds.
The light pnictogens (nitrogen, phosphorus, and arsenic) tend to form −3 charges when reduced, completing their octet. When oxidized or ionized, pnictogens typically take an oxidation state of +3 (by losing all three p-shell electrons in the valence shell) or +5 (by losing all three p-shell and both s-shell electrons in the valence shell).
Chemical symbols are the abbreviations used in chemistry, mainly for chemical elements; but also for functional groups, chemical compounds, and other entities. Element symbols for chemical elements, also known as atomic symbols, normally consist of one or two letters from the Latin alphabet and are written with the first letter capitalised.
Tetrapolyphosphoric acid H 6 P 4 O 13 yields at least six anions, including tetrapolyphosphate [P 4 O 13] 6−, and so on. Note that each extra phosphoric unit adds one extra P atom, three extra O atoms, and either one extra hydrogen atom or an extra negative charge. Branched polyphosphoric acids give similarly branched polyphosphate anions.
It is a tabular arrangement of the elements by their chemical properties that usually uses abbreviated chemical symbols in place of ... [p] 13 2 p-block: 10.81: 2.34 ...
This may lead to deposition of residual charge on the screen, effectively decreasing the energy of the impacting electrons due to electrostatic repulsion (an effect known as "sticking"). To eliminate this, a thin layer of aluminium (about 100 nm) is deposited over the phosphors, usually by vacuum evaporation, and connected to the conductive ...