chemical element wi the atomic nummer o 12

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, 12Mg
Template:Infobox element/symbol-to-top-image/alt
Pronunciation/mæɡˈnziəm/ (mag-NEE-zee-əm)
Appearanceshiny gray solit
Standard atomic weight Ar, std(Mg)[24.30424.307] conventional: 24.305
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


Atomic nummer (Z)12
Groupgroup 2 (alkaline yird metals)
Periodperiod 3
Element category  Alkaline yird metal
Electron confeeguration[Ne] 3s2
Electrons per shell2, 8, 2
Pheesical properties
Phase at STPsolit
Meltin pynt923 K ​(650 °C, ​1202 °F)
Bylin pynt1363 K ​(1091 °C, ​1994 °F)
Density (near r.t.)1.738 g/cm3
when liquid (at m.p.)1.584 g/cm3
Heat o fusion8.48 kJ/mol
Heat o vapourisation128 kJ/mol
Molar heat capacity24.869 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+1,[1] +2 strangly basic
ElectronegativityPauling scale: 1.31
Ionisation energies
  • 1st: 737.7 kJ/mol
  • 2nd: 1450.7 kJ/mol
  • 3rd: 7732.7 kJ/mol
  • (more)
Atomic radiusempirical: 160 pm
Covalent radius141±7 pm
Van der Waals radius173 pm
Colour lines in a spectral range
Colour lines in a spectral range
Spectral lines o magnesium
Ither properties
Naitural occurrenceprimordial
Creestal structurhexagonal close-packed (hcp)
Hexagonal close packed creestal structur for magnesium
Speed o soond thin rod4940 m/s (at r.t.) (annealed)
Thermal expansion24.8 µm/(m·K) (at 25 °C)
Thermal conductivity156 W/(m·K)
Electrical resistivity43.9 nΩ·m (at 20 °C)
Magnetic orderinparamagnetic
Magnetic susceptibility+13.1·10−6 cm3/mol (298 K)[2]
Young's modulus45 GPa
Shear modulus17 GPa
Bulk modulus35.4[3] GPa
Poisson ratio0.290
Mohs haurdness1–2.5
Brinell haurdness44–260 MPa
CAS Nummer7439-95-4
Naminafter Magnesia, Greece
DiskiveryJoseph Black (1755)
First isolationHumphry 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

Magnesium is the nint maist abundant element in the universe.[6][7] It is produced in muckle, 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[8] an the fowerth maist common element in the Yird (efter airn, oxygen an silicon), makkin up 13% o the planet's mass an a muckle fraction o the planet's mantle. It is the third maist abundant element dissolved in seawater, efter sodium an chlorine.[9]

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.[10] 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.[10]


  1. 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.
  2. Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.
  3. K. A. Gschneider, Solid State Phys. 16, 308 (1964)
  4. Meija, Juris; 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.
  5. 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.
  6. Housecroft, C. E.; Sharpe, A. G. (2008). Inorganic Chemistry (3rd ed.). Prentice Hall. pp. 305–306. ISBN 978-0131755536.
  7. Ash, Russell (2005). The Top 10 of Everything 2006: The Ultimate Book of Lists. Dk Pub. ISBN 0-7566-1321-3. Archived frae the original on 5 October 2006.
  8. "Abundance and form of the most abundant elements in Earth's continental crust" (PDF). Archived frae the original (PDF) on 27 September 2011. Retrieved 15 Februar 2008. Cite journal requires |journal= (help)
  9. Anthoni, J Floor (2006). "The chemical composition of seawater".
  10. a b "Dietary Supplement Fact Sheet: Magnesium". Office of Dietary Supplements, US National Institutes of Health. 11 Februar 2016. Retrieved 13 October 2016.