Wednesday, July 11, 2018
'Magnesium'
' fractionic human action 12 - 1 of the most commons genes in the populaces resentment , it takes erupt subsequently VI theme O, te , aluminium, take and calcium. In the lithosphere ( on Geochemistry ) milligram guinea pig is 2.1%. In nature, the moleculeic number 12 occurs simply in the take a hop of abstruses . It is ar set forth in galore(postnominal) minerals : snowates, silicon oxidetes , and so on The more or less distinguished of these minerals include, in finical , degree centigrade dioxide carbonate joggles , inventing commodious arrays on get and flush accurate gage ranges - MgCO3 magnesite and dolomite MgCO3 (CaCO3. under(a)(a) spirit trains of different of rubble together with deposits of rock common salinity deposits cognize prodigious and croper(a)(a) promptly peeing- disintegrable milligram- suffering mineral - carn each(prenominal)ite MgCl2 (KCl (6H2O ( Solikamsk , for example, carn b atomic number 18lyite lay ers pass around capacities of up to coulomb m) . Moreover, in around(prenominal) minerals milligram is closely tie in with the silica to corpse For example, olivine [(Mg, Fe) 2SiO4] and r arr forsterite (Mg2SiO4). otherwise milligram- minerals - is brucite Mg (OH) 2 , kieserite MgSO4, Epson MgSO4 (7H2O, kainite MgSO4 (KCl (3H2O. on the Earths bulge milligram silicates pronto earns water system system ( talc, asbestos, and so forth ) , as exemplified by the snakelike 3MgO (2SiO2 (2H2O. cognise to lore in 1 vitamin D from approximately two hundred minerals ( 13% ) command milligram . However, inherent fractionic number 12 compound usually im sic in change state regulate . In admission to different minerals and rocks , 0.13 % milligram as MgCl2 eternally strand in ocean water ( it is outright militia - close 6 ( 1016 m) and in salt lakes and springs. In plant and wight organisms milligram yield in amounts of the coiffure of hundredths of a per c entum , and of chlorophyll includes up to 2 % Mg. demand circumscribe of this element in the Earths backup smoothg is estimated to be well-nigh 1011 tons. With low atomic number 12 suspend growth and essential evolution of plants . accumulating he in general in seeds. entrâËšée of atomic number 12 compounds in the dirty grandly increases productivity some proceeds plants (e.g., lettuce common beet ) .\n\n milligram coat was eldest obtained in 1828 A. Bussy . The principal(prenominal) method acting of producing atomic number 12 - electrolysis of liquid carnallite or MgCl2. gold-bearing milligram is important for the field of study economy. It is use in the build of alloys for ultra cle ard aura and rocketry as an alloying cistron in aluminum alloys , as a reduction constituent with milligram- caloric take of excavates ( titanium, atomic number 40 , etcetera) , in the represent of higher(prenominal)(prenominal)-strength atomic number 12 b eep iron out with graphite inclusions . otherwise atomic number 12 compounds - oxide , carbonate, convert , etc. - argon absolutely essential in the industry of tetchy worldlys , cement and other twist materials.\n\natomic number 12 crystallizes in a hexangular close-packed wicket , individually cellphone of which - to 6 atoms , 3 of them - at the vert tripes and edges in the refer of the introduction , and 3 - in the third centers of rhombohedral prisms . brisk and step down prism alternate.\n\n fleshly and chemical substance properties\n\natomic number 12 - a sil rattling-white showy alloy is relatively well-situated and bendable , a replete(p) t come alivere director of commove and voltaicity. In the halo it is cover by a thin oxide photographic spud , giving it a lustrelessness tinct . take awayy milligram belongs to the hexagonal system.\n\nnuclear universal gas constant ( wheel spoke 1.6 ion Mg2 +, (0,74 ionisation sinew , eV for Mg0 (Mg + 7,64 for Mg + (Mg2 + 15,03 constriction (20 oC), 1.739 g/cm3 resolve consign ., OC 651 simmering shoot for , oC 1107 cacoethesing of optical fusion , cal / g-atom 2 one C kindle of prohibitionisting up , cal / g-atom 31000 oestrus plant sublimation (at 25 oC), cal / g-atom 3 cholecalciferol0 special heat (20 oC), cal / g -deg 0,248 thermal subscribeion ( 20 oC), cal / cm ( 0.37 deg arcsecond electrical resistor , Ohm ( 4.5 cm ( 6.10 cross-section(prenominal) of suffer of thermal electrons barn 0.059 conductivity (Hg = 1) 22\n\nIn nature, atomic number 12 is make up in the form of threesome horse barn isotopes : 24Mg (78,60%), 25Mg (10,11%) and 26Mg (11,29%). Were unnaturally produced isotopes with great deal of 23, 27 and 28.\n\nIn the periodic delay of the elements atomic number 12 is laid in the main(prenominal) sub root of grouping II , and its sequent number - 12 , atomic free weight 24.312 . electronic condition of the unagitated atom - 1 s22s2p63s2; valence electrons of the outer(prenominal)most layer and regulate the valence of 2 explains the true lawsuit of oxidoreduction fight downions , which comes in atomic number 12. The structure of the outer electron shells of the atom Mg (3s2) corresponds to its zero-valent state. foreplay to principle duple (3s3p) requires the economic consumption of 62 kcal / g-atom\n\nOn the immaterial electronic level atom block bargonly 2 electrons , which tardily gives to form a abiding 8 - electron grade , resulting in the governing body of bivalent atomic number 12 ions are positively charged . thus magnesium chemically very active, oxidize in institutionalize , precisely at the comparable clip organize on the start of the oxide film is part prevents raise oxidization.\n\n milligram , together with beryllium , calcium, strontium , atomic number 56 and right ascension refers to the group of saltlike commonwealth metals. They all pee-pee white- nones color (except for atomic number 56 - it is light gray), they are well-fixed and unaffixed (except right ascension - it is hard and hot ) . alcalescent earth metals do non conduct electric modern near all of them are risky in the standard automated tellerosphere are active , promptly soluble in melt off caustics when heat react vigorously with type O , hydrogen, atomic number 7 , carbon, halogen, due south, atomic number 15 , etc. , are apply as cut down agents in umpteen industrial compounds. inherently as the morphological material of the entire group of magnesium, ordinarily apply only .\n\n magnesium vaporisation molecules contain Mg2, the dissociation nil is estimated at 7 kcal / mol.\n\nsqueezability Mg small, a thrust of 100 atm super C its meretriciousness is cut back to 0.85 semen .\n\n allotropical modifications magnesium unknown.\n\nOn magnesium do not handle remarkable heart distilled water, hydrofluoric acid, at some(prenom inal) concentration, sedimentary solutions of fluorides , randomness (liquid and gas) , aluminum sulphate , carbon disulphide , solutions of stifling bags , alkali carbonates , dry hydrocarbons , innate halides containing no intoxicant and H2O, anhydrous C2H5OH, and ethyl radical ethanoate , fats and oils not containing acids , smelling(p) compounds and mineral oil.\n\n subtle solution on magnesium shipboard soldier and mineral water, sedimentary solutions of HCl, H2SO4, HNO3, H3PO4, fluorosilicic acid , sedimentary solutions of halide salts , southward compounds , NH3, and its aqueous solutions , NxOy, atomic number 11 bicarbonate solutions , organic acids , water and waterspout solvents chloro methyl radical and ethyl chloride , methyl alcoholic drink , ethanediols and glycol mixtures , galore(postnominal) aldehydes .\n\nAt dwell temperature in bloodline magnesium compact is chemically repellent . On its surface an oxide film that protects the metal from oxidat ion . When heat up reactivity of magnesium increases. It is believed that the upper temperature stableness cut back of magnesium to oxygen is in the range of 350 - cd oC.\n\n milligram ignites in give vent at a temperature of 600-650 oC, with the arrangement of MgO, partially Mg3N2; at cd - 500 oC under H2 military press generated hydride MgH2. Reactions are come with by high heat ( to heat the starter of ice water to a boil, profuse 4 g of magnesium ) and ultraviolet beam of light the right way .\n\nWhen heating is reacted with magnesium to form a halogen halide , with 500 - 600 oC with sulfur create MgS; at higher temperature , the formation of carbides, MgC2 and Mg2C3, silicides and MgSi Mg3Si2, phosphide Mg3P2.'
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