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Diamond and graphite are two allotropes of carbon: pure forms of the same element that differ in crystalline structure.. Allotropy or allotropism (from Ancient Greek ἄλλος (allos) 'other' and τρόπος (tropos) 'manner, form') is the property of some chemical elements to exist in two or more different forms, in the same physical state, known as allotropes of the elements.
The main food sources for phosphorus are the same as those containing protein, although proteins do not contain phosphorus. For example, milk, meat, and soya typically also have phosphorus. As a rule, if a diet has sufficient protein and calcium, the amount of phosphorus is probably sufficient. [143]
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Dietary fibre from fruits, vegetables and grain foods. Insoluble dietary fibre is not absorbed in the human digestive tract but is important in maintaining the bulk of a bowel movement to avoid constipation. [5] Soluble fibre can be metabolized by bacteria residing in the large intestine.
White phosphorus, yellow phosphorus, or simply tetraphosphorus (P 4) is an allotrope of phosphorus.It is a translucent waxy solid that quickly yellows in light (due to its photochemical conversion into red phosphorus), [2] and impure white phosphorus is for this reason called yellow phosphorus.
These allotropes have been synthesised by various methods for example, treating titanocene pentasulfide and a dichlorosulfane of suitable sulfur chain length, S n−5 Cl 2: [17] (η 5-C 5 H 5) 2 TiS 5 + S n−5 Cl 2 → cyclo-S n + (η 5-C 5 H 5) 2 TiCl 2. or alternatively treating a dichlorosulfane, S n−m Cl 2 and a polysulfane, H 2 S m: [17 ...
The diphosphorus allotrope (P 2) can normally be obtained only under extreme conditions (for example, from P 4 at 1100 kelvin). In 2006, the diatomic molecule was generated in homogeneous solution under normal conditions with the use of transition metal complexes (for example, tungsten and niobium ).
A fullerene is an allotrope of carbon whose molecules consist of carbon atoms connected by single and double bonds so as to form a closed or partially closed mesh, with fused rings of five to six atoms. The molecules may have hollow sphere- and ellipsoid-like forms, tubes, or other shapes.