Magnesium

Magnesium, ₁₂Mg
Magnesium
Pronunciation	/mæɡˈniːziəm/ (mag-NEE-zee-əm)
Appearance	shiny gray solit
Standard atomic weight Ar, std(Mg)	[24.304, 24.307] conventional: 24.305
Magnesium in the periodic cairt
	sodium ← magnesium → alumeenium
Atomic nummer (Z)	12
Group	group 2 (alkaline yird metals)
Period	period 3
Block	s-block
Element category	Alkaline yird metal
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)
Atomic properties
Oxidation states	+1, +2 strangly basic
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
	Colour lines in a spectral rangeSpectral lines o magnesium
Ither properties
Naitural occurrence	primordial
Creestal structur	hexagonal close-packed (hcp)
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)
Young's modulus	45 GPa
Shear modulus	17 GPa
Bulk modulus	35.4 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
	view; talk; edit; \| references

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.^[4]^[5] 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^[6] 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.^[7]

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.^[8] 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.^[8]

References

↑ 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.
↑ Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.
↑ K. A. Gschneider, Solid State Phys. 16, 308 (1964)
↑ Housecroft, C. E.; Sharpe, A. G. (2008). Inorganic Chemistry (3rd ed.). Prentice Hall. pp. 305–306. ISBN 978-0131755536.
↑ 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.
↑ "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)
↑ Anthoni, J Floor (2006). "The chemical composition of seawater". seafriends.org.nz.
1 2 "Dietary Supplement Fact Sheet: Magnesium". Office of Dietary Supplements, US National Institutes of Health. 11 Februar 2016. Retrieved 13 October 2016.

[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] Housecroft, C. E.; Sharpe, A. G. (2008). Inorganic Chemistry (3rd ed.). Prentice Hall. pp. 305–306. ISBN 978-0131755536.

[5] 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.

[Abundance-6] "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)

[7] Anthoni, J Floor (2006). "The chemical composition of seawater". seafriends.org.nz.

[nih-8] 1 2 "Dietary Supplement Fact Sheet: Magnesium". Office of Dietary Supplements, US National Institutes of Health. 11 Februar 2016. Retrieved 13 October 2016.

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