Magnesium

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Magnesium,  12Mg
CSIRO ScienceImage 2893 Crystalised magnesium.jpg
General properties
Appearance shiny gray solit
Staundart atomic wecht (Ar, staundart) [24.30424.307] conventional: 24.305[1]
Magnesium in the periodic cairt
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Airn Cobalt Nickel Capper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Siller (element) Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gowd Mercur (element) Thallium Leid (element) Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Ununtrium Flerovium Ununpentium Livermorium Ununseptium Ununoctium
Be

Mg

Ca
sodiummagnesiumalumeenium
Atomic nummer (Z) 12
Group group 2 (alkaline yird metals)
Period period 3
Element category   alkalineearthmetal
Block s-block
Electron confeeguration [Ne] 3s2
Electrons per shell
2, 8, 2
Pheesical properties
Phase (at STP) solit
Meltin pynt 923 K ​(650 °C, ​1202 °F)
Bylin pynt 1363 K ​(1091 °C, ​1994 °F)
Density (near r.t.) 1.738 g/cm3
when liquid (at m.p.) 1.584 g/cm3
Heat o fusion 8.48 kJ/mol
Heat o vapourisation 128 kJ/mol
Molar heat capacity 24.869 J/(mol·K)
Vapour pressur
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 701 773 861 971 1132 1361
Atomic properties
Oxidation states +2, +1[2] ​(a strangly basic oxide)
Electronegativity Pauling scale: 1.31
Ionisation energies
  • 1st: 737.7 kJ/mol
  • 2nd: 1450.7 kJ/mol
  • 3rd: 7732.7 kJ/mol
  • (more)
Atomic radius empirical: 160 pm
Covalent radius 141±7 pm
Van der Waals radius 173 pm
Color lines in a spectral range
Miscellanea
Creestal structurhexagonal close-packed (hcp)
Hexagonal close packed creestal structur for magnesium
Speed o soond thin rod 4940 m/s (at r.t.) (annealed)
Thermal expansion 24.8 µm/(m·K) (at 25 °C)
Thermal conductivity 156 W/(m·K)
Electrical resistivity 43.9 nΩ·m (at 20 °C)
Magnetic orderin paramagnetic
Magnetic susceptibility +13.1·10−6 cm3/mol (298 K)[3]
Young's modulus 45 GPa
Shear modulus 17 GPa
Bouk modulus 35.4[4] GPa
Poisson ratio 0.290
Mohs haurdness 1–2.5
Brinell haurdness 44–260 MPa
CAS Nummer 7439-95-4
History
Namin after Magnesia, Greece
Diskivery Joseph Black (1755)
First isolation Humphry Davy (1808)
Main isotopes o magnesium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
24Mg 79.0% stable
25Mg 10.0% stable
26Mg 11.0% stable
| references | in Wikidata

Magnesium is a chemical element wi seembol Mg an atomic nummer 12. It is a shiny gray solit which bears a close pheesical resemblance tae the ither five elements in the seicont column (Group 2, or alkaline yird metals) o the periodic cairt: thay each hae the same electron confeeguration in thair ooter electron shell producin a seemilar crystal structur.

Magnesium is the nint maist abundant element in the universe.[5][6] It is produced in lairge, agein starns frae the sequential addeetion o three helium nuclei tae a caurbon nucleus. Whan sic starns explode as supernovas, muckle o the magnesium is expelled intae the interstellar medium whaur it mey recycle intae new starn seestems. Magnesium is the aicht maist abundant element in the Yird's crust[7] an the fowerth maist common element in the Yird (efter airn, oxygen an silicon), makkin up 13% o the planet's mass an a lairge fraction o the planet's mantle. It is the third maist abundant element dissolved in seawater, efter sodium an chlorine.[8]

Magnesium occurs naiturally anly in combination wi ither elements, whaur it invariably has a +2 oxidation state. The free element (metal) can be produced artifeecially, an is heichly reactive (tho in the atmosphere, it is suin coatit in a thin layer o oxide that pairtly inhibits reactivity — see passivation). The free metal birns wi a chairactereestic brilliant-white licht. The metal is nou obteened mainly bi electrolysis o magnesium sauts obteened frae brack, an is uised primarily as a component in alumeenium-magnesium alloys, whiles cried magnalium or magnelium. Magnesium is less dense nor alumeenium, an the alloy is prized for its combination o lichtness an strenth.

Magnesium is the eleivent maist abundant element bi mass in the human bouk an is essential tae aw cells an some 300 enzymes.[9] Magnesium ions interact wi polyphosphate compoonds sic as ATP, DNA, an RNA. Hunders o enzymes require magnesium ions tae function. Magnesium compoonds are uised medicinally as common laxatives, antacids (e.g., milk o magnes), an tae stabilise abnormal nerve excitation or bluid veshel spasm in sic condeetions as eclampsia.[9]

References[eedit | eedit soorce]

  1. Meija, J.; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305. 
  2. Bernath, P. F.; Black, J. H. & Brault, J. W. (1985). "The spectrum of magnesium hydride" (PDF). Astrophysical Journal. 298: 375. Bibcode:1985ApJ...298..375B. doi:10.1086/163620. 
  3. Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4. 
  4. K. A. Gschneider, Solid State Phys. 16, 308 (1964)
  5. Housecroft, C. E.; Sharpe, A. G. (2008). Inorganic Chemistry (3rd ed.). Prentice Hall. pp. 305–306. ISBN 978-0131755536. 
  6. Ash, Russell (2005). The Top 10 of Everything 2006: The Ultimate Book of Lists. Dk Pub. ISBN 0-7566-1321-3. Archived frae the oreeginal on 2006-10-05. 
  7. "Abundance and form of the most abundant elements in Earth's continental crust" (PDF). Retrieved 15 February 2008. 
  8. Anthoni, J Floor (2006). "The chemical composition of seawater". seafriends.org.nz. 
  9. 9.0 9.1 "Dietary Supplement Fact Sheet: Magnesium". Office of Dietary Supplements, US National Institutes of Health. 11 February 2016. Retrieved 13 October 2016.