Magnesium


Magnesium
sodiummagnesiumaluminium
Be

Mg

Ca
Appearance
shiny grey solid


Spectral lines of Magnesium
General properties
Name, symbol, number magnesium, Mg, 12
Pronunciation /mæɡˈnziəm/, mag-nee-zee-əm
Element category alkaline earth metal
Group, period, block 2, 3, s
Standard atomic weight 24.3050(6)
Electron configuration [Ne] 3s2
Electrons per shell 2, 8, 2 (Image)
Physical properties
Phase solid
Density (near r.t.) 1.738 g·cm−3
Liquid density at m.p. 1.584 g·cm−3
Melting point 923 K, 650 °C, 1202 °F
Boiling point 1363 K, 1091 °C, 1994 °F
Heat of fusion 8.48 kJ·mol−1
Heat of vaporization 128 kJ·mol−1
Molar heat capacity 24.869 J·mol−1·K−1
Vapor pressure
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 [1]
(strongly basic oxide)
Electronegativity 1.31 (Pauling scale)
Ionization energies
(more)
1st: 737.7 kJ·mol−1
2nd: 1450.7 kJ·mol−1
3rd: 7732.7 kJ·mol−1
Atomic radius 160 pm
Covalent radius 141±7 pm
Van der Waals radius 173 pm
Miscellanea
Crystal structure hexagonal
Magnetic ordering paramagnetic
Electrical resistivity (20 °C) 43.9 nΩ·m
Thermal conductivity 156 W·m−1·K−1
Thermal expansion (25 °C) 24.8 µm·m−1·K−1
Speed of sound (thin rod) (r.t.) (annealed)
4940 m·s−1
Young's modulus 45 GPa
Shear modulus 17 GPa
Bulk modulus 45 GPa
Poisson ratio 0.290
Mohs hardness 2.5
Brinell hardness 260 MPa
CAS registry number 7439-95-4
Most stable isotopes
Main article: Isotopes of magnesium
iso NA half-life DM DE (MeV) DP
24Mg 78.99% 24Mg is stable with 12 neutrons
25Mg 10% 25Mg is stable with 13 neutrons
26Mg 11.01% 26Mg is stable with 14 neutrons
v ·  /mæɡˈnziəm/ mag-nee-zee-əm) is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust, where it constitutes about 2% by mass,[2] and ninth in the known universe as a whole.[3][4] This abundance of magnesium is related to the fact that it is easily built up in supernova stars from a sequential addition of three helium nuclei to carbon (which in turn is made from three helium nuclei). Due to magnesium ion's high solubility in water, it is the third most abundant element dissolved in seawater.[5]

Magnesium is the 11th most abundant element by mass in the human body; its ions are essential to all living cells, where they play a major role in manipulating important biological polyphosphate compounds like ATP, DNA, and RNA. Hundreds of enzymes thus require magnesium ions to function. Magnesium is also the metallic ion at the center of chlorophyll, and is thus a common additive to fertilizers.[6] Magnesium compounds are used medicinally as common laxatives, antacids (e.g., milk of magnesia), and in a number of situations where stabilization of abnormal nerve excitation and blood vessel spasm is required (e.g., to treat eclampsia). Magnesium ions are sour to the taste, and in low concentrations help to impart a natural tartness to fresh mineral waters.

The free element (metal) is not found naturally on Earth, as it is highly reactive (though once produced, it is coated in a thin layer of oxide [see passivation], which partly masks this reactivity). The free metal burns with a characteristic brilliant white light, making it a useful ingredient in flares. The metal is now mainly obtained by electrolysis of magnesium salts obtained from brine. Commercially, the chief use for the metal is as an alloying agent to make aluminium-magnesium alloys, sometimes called "magnalium" or "magnelium". Since magnesium is less dense than aluminium, these alloys are prized for their relative lightness and strength.

Contents

Origin and characteristics

Physical and chemical properties

Elemental magnesium is a fairly strong, silvery-white, light-weight metal (two thirds the density of aluminium). It tarnishes slightly when exposed to air, although unlike the alkali metals, storage in an oxygen-free environment is unnecessary because magnesium is protected by a thin layer of oxide that is fairly impermeable and difficult to remove. Like its lower periodic table group neighbor calcium, magnesium reacts with water at room temperature, though it reacts much more slowly than calcium. When submerged in water, hydrogen bubbles will almost unnoticeably begin to form on the surface of the metal, though if powdered it will react much more rapidly. The reaction will occur faster with higher temperatures (see precautions). Magnesium's ability to react with water can be harnessed to produce energy and run a magnesium-based engine. Magnesium also reacts exothermically with most acids, such as hydrochloric acid (HCl). As with aluminium, zinc and many other metals, the reaction with hydrochloric acid produces the chloride of the metal and releases hydrogen gas.

Magnesium is a highly flammable metal, but while it is easy to ignite when powdered or shaved into thin strips, it is difficult to ignite in mass or bulk. Once ignited, it is difficult to extinguish, being able to burn in nitrogen (forming magnesium nitride), carbon dioxide (forming magnesium oxide and carbon) and water (forming magnesium oxide and hydrogen). This property was used in incendiary weapons used in the firebombing of cities in World War II, the only practical civil defense being to smother a burning flare under dry sand to exclude the atmosphere. On burning in air, magnesium produces a brilliant white light which includes strong ultraviolet. Thus magnesium powder (flash powder) was used as a source of illumination in the early days of photography. Later, magnesium ribbon was used in electrically ignited flash bulbs. Magnesium powder is used in the manufacture of fireworks and marine flares where a brilliant white light is required. Flame temperatures of magnesium and magnesium alloys can reach 3,100 °C (3,370 K; 5,610 °F),[7] although flame height above the burning metal is usually less than 300 mm (12 in).[8] Magnesium may be used as an ignition source for thermite, an otherwise difficult to ignite mixture of aluminium and iron oxide powder.

Magnesium compounds are typically white crystals. Most are soluble in water, providing the sour-tasting magnesium ion Mg2+. Small amounts of dissolved magnesium ion contribute to the tartness and taste of natural waters. Magnesium ion in large amounts is an ionic laxative, and magnesium sulfate (common name: Epsom salt) is sometimes used for this purpose. So-called "milk of magnesia" is a water suspension of one of the few insoluble magnesium compounds, magnesium hydroxide. The undissolved particles give rise to its appearance and name. Milk of magnesia is a mild base commonly used as an antacid, which has some laxative side effect.

Isotopes

Magnesium has three stable isotopes: 24Mg, 25Mg and 26Mg. All are present in significant amounts (see table of isotopes above). About 79% of Mg is 24Mg. The isotope 28Mg is radioactive and in the 1950s to 1970s was made commercially by several nuclear power plants for use in scientific experiments. This isotope has a relatively short half-life (21 hours) and so its use was limited by shipping times.

26Mg has found application in isotopic geology, similar to that of aluminium. 26Mg is a radiogenic daughter product of 26Al, which has a half-life of 717,000 years. Large enrichments of stable 26Mg have been observed in the Ca-Al-rich inclusions of some carbonaceous chondrite meteorites. The anomalous abundance of 26Mg is attributed to the decay of its parent 26Al in the inclusions. Therefore, the meteorite must have formed in the solar nebula before the 26Al had decayed. Hence, these fragments are among the oldest objects in the solar system and have preserved information about its early history.

It is conventional to plot 26Mg/24Mg against an Al/Mg ratio. In an isochron dating plot, the Al/Mg ratio plotted is27Al/24Mg. The slope of the isochron has no age significance, but indicates the initial 26Al/27Al ratio in the sample at the time when the systems were separated from a common reservoir.

Creation

Stable forms of magnesium are produced in stars. It is made from fusing helium and neon, in the so-called alpha process. Creation requires temperatures above 600 megakelvins and masses greater than 3 solar masses.

Occurrence

Country 2010 production
(tonnes)[9]
China 650,000
Russia 40,000
Israel 30,000
Kazakhstan 20,000
Brazil 16,000
Ukraine 2,000
Serbia 2,000

Although magnesium is found in over 60 minerals, only dolomite, magnesite, brucite, carnallite, talc, and olivine are of commercial importance.

The Mg2+ cation is the second most abundant cation in seawater (occurring at about 12% of the mass of sodium there), which makes seawater and sea-salt an attractive commercial source of Mg. To extract the magnesium, calcium hydroxide is added to seawater to form magnesium hydroxide precipitate.

MgCl2 + Ca(OH)2Mg(OH)2 + CaCl2

Magnesium hydroxide (brucite) is insoluble in water so it can be filtered out, and reacted with hydrochloric acid to obtain concentrated magnesium chloride.

Mg(OH)2 + 2 HCl → MgCl2 + 2 H2O

From magnesium chloride, electrolysis produces magnesium.

In the United States, magnesium is principally obtained by electrolysis of fused magnesium chloride from brines, wells, and sea water. At the cathode, the Mg2+ ion is reduced by two electrons to magnesium metal:

Mg2+ + 2 e
→ Mg

At the anode, each pair of Cl ions is oxidized to chlorine gas, releasing two electrons to complete the circuit:

2 ClCl2 (g) + 2 e

The United States has traditionally been the major world supplier of this metal, supplying 45% of world production even as recently as 1995. Today, the US market share is at 7%, with a single domestic producer left, US Magnesium, a Renco Group company in Utah born from now-defunct Magcorp.[10]

As of 2005, China has taken over as the dominant supplier, pegged at 60% world market share, which increased from 4% in 1995. Unlike the above-described electrolytic process, China is almost completely reliant on a different method of obtaining the metal from its ores, the silicothermic Pidgeon process (the reduction of the oxide at high temperatures with silicon).[citation needed]

History

The name magnesium originates from the Greek word for a district in Thessaly called Magnesia. It is related to magnetite and manganese, which also originated from this area, and required differentiation as separate substances. See manganese for this history.

Magnesium is the seventh most abundant element in the Earth's crust by mass or molarity.[2] It is found in large deposits of magnesite, dolomite, and other minerals, and in mineral waters, where magnesium ion is soluble. In 1618, a farmer at Epsom in England attempted to give his cows water from a well there. The cows refused to drink because of the water's bitter taste, but the farmer noticed that the water seemed to heal scratches and rashes. The substance became known as Epsom salts and its fame spread; it was eventually recognized to be hydrated magnesium sulfate, MgSO4.

The metal itself was first produced by Sir Humphry Davy in England in 1808 using electrolysis of a mixture of magnesia and mercury oxide.[11] Antoine Bussy prepared it in coherent form in 1831. Davy's first suggestion for a name was magnium, but the name magnesium is now used.[citation needed]

Applications

As Metal

An unusual application of magnesium as an illumination source while wakeskating in 1931

Magnesium is the third most commonly used structural metal, following iron and aluminium. It has been called the lightest useful metal by The Periodic Table of Videos.[12]

The main applications of magnesium are, in order: component of aluminium alloys, in die-casting (alloyed with zinc),[13] to remove sulfur in the production of iron and steel, the production of titanium in the Kroll process.[14]

Magnesium, in its purest form, can be compared with aluminium, and is strong and light, so it is used in several high volume part manufacturing applications, including automotive and truck components. Specialty, high-grade car wheels of magnesium alloy are called "mag wheels", although the term is often more broadly misapplied to include aluminum wheels. In 1957, a Corvette SS, designed for racing, was constructed with magnesium body panels. An earlier Mercedes-Benz race car model, the Mercedes-Benz 300 SLR, had a body made from Elektron, a magnesium alloy; these cars ran (with successes) at Le Mans, the Mille Miglia, and other world-class race events in 1955 (though one was involved in the single worst accident in auto racing history, in terms of human casualties, at the Le Mans race.) Porsche's all-out quest to decrease the weight of their race cars led to the use of magnesium frames in the famous 917/053 that won Le Mans in 1971, and still holds the absolute distance record. The 917/30 Can-Am car also featured a magnesium frame, helping it to make the most of its prodigious 1100–1500 hp. Volkswagen Group has used magnesium in its engine components for many years. For a long time, Porsche used magnesium alloy for its engine blocks due to the weight advantage. There is renewed interest in magnesium engine blocks, as featured in the 2006 BMW 325i and 330i models. The BMW engine uses an aluminium alloy insert for the cylinder walls and cooling jackets surrounded by a high-temperature magnesium alloy AJ62A. The application of magnesium AE44 alloy in the 2006 Corvette Z06 engine cradle has advanced the technology of designing robust automotive parts in magnesium. Both these alloys are recent developments in high-temperature low creep magnesium alloys. Mitsubishi Motors also uses magnesium (branded magnesium alloy) for its paddle shifters. The general strategy for such alloys is to form intermetallic precipitates at the grain boundaries, for example by adding mischmetal or calcium.[15] New alloy development and lower costs, which are becoming competitive to aluminium, will further the number of automotive applications.[citation needed]

Products made of magnesium: firestarter and shavings, sharpener, magnesium ribbon

The second application field of magnesium is electronic devices. Because of low weight, good mechanical and electrical properties, magnesium is widely used for manufacturing of mobile phones, laptop computers, cameras, and other electronic components.

Historically, magnesium was one of the main aerospace construction metals and was used for German military aircraft as early as World War I and extensively for German aircraft in World War II. The Germans coined the name 'Elektron' for magnesium alloy. The term is still used today. Because of perceived hazards with magnesium parts in the event of fire, the application of magnesium in the commercial aerospace industry was generally restricted to engine related components. Currently the use of magnesium alloys in aerospace is increasing, mostly driven by the increasing importance of fuel economy and the need to reduce weight.[citation needed] The development and testing of new magnesium alloys continues, notably Elektron 21, which has successfully undergone extensive aerospace testing for suitability in engine, internal and airframe components. The European Community runs three R&D magnesium projects in the Aerospace priority of Six Framework Program.

Niche Uses of the Metal

Magnesium, being available and relatively nontoxic, has variety of uses:

  • Magnesium is flammable, burning at a temperature of approximately 3,100 °C (3,370 K; 5,610 °F),[7] and the autoignition temperature of magnesium ribbon is approximately 630 °C (903 K; 1,166 °F) in air.[16] It produces intense, bright, white light when it burns. Magnesium's high burning temperature makes it a useful tool for starting emergency fires during outdoor recreation. Other uses include flash photography, flares, pyrotechnics and fireworks sparklers.
    Magnesium firestarter (in left hand), used with a pocket knife and flint to create sparks that ignite the shavings
  • In the form of turnings or ribbons, to prepare Grignard reagents, which are useful in organic synthesis.
  • As an additive agent in conventional propellants and the production of nodular graphite in cast iron.
  • As a reducing agent for the production of uranium and other metals from their salts.
  • As a sacrificial (galvanic) anode to protect underground tanks, pipelines, buried structures, and water heaters.
  • Alloyed with zinc to produce the zinc sheet used in photoengraving plates in the printing industry, dry-cell battery walls, and roofing.[13]
  • As a metal, this element's principal use is as an alloying additive to aluminium with these aluminium-magnesium alloys being used mainly for beverage cans.

As Magnesium Compounds

The magnesium ion is necessary for all life (see magnesium in biology), so magnesium salts are frequently included in various foods, fertilizers (magnesium is a component of chlorophyll), and culture media.

Magnesium compounds, primarily magnesium oxide (MgO), are used as refractory a material in furnace linings for producing iron, steel, nonferrous metals, glass and cement. Magnesium oxide and other magnesium compounds are also used in the agricultural, chemical, and construction industries.

Magnesium reacted with an alkyl halide gives a Gringard reagent, which is a very useful tool for preparing alcohols.

Niche and Illustrative Uses of Magnesium Compounds

Biological role

Because of the important interaction between phosphate and magnesium ions, magnesium ions are essential to the basic nucleic acid chemistry of life, and thus are essential to all cells of all known living organisms. Over 300 enzymes require the presence of magnesium ions for their catalytic action, including all enzymes utilizing or synthesizing ATP, or those that use other nucleotides to synthesize DNA and RNA. ATP exists in cells normally as a chelate of ATP and a magnesium ion.

Plants have an additional use for magnesium in that chlorophylls are magnesium-centered porphyrins. Magnesium deficiency in plants causes late-season yellowing between leaf veins, especially in older leaves, and can be corrected by applying Epsom salts (which is rapidly leached), or else crushed dolomitic limestone to the soil.

Examples of food sources of magnesium

Magnesium is a vital component of a healthy human diet. Human magnesium deficiency (including conditions that show few overt symptoms) is relatively rare[17] although only 32% of the United States meet the RDA-DRI;[18] low levels of magnesium in the body has been associated with the development of a number of human illnesses such as asthma, diabetes, and osteoporosis.[19]

Adult human bodies contain about 24 grams of magnesium, with 60% in the skeleton, 39% intracellular (20% in skeletal muscle), and 1% extracellular. Serum levels are typically 0.7–1.0 mmol/L or 1.8–2.4 mEq/L. Serum magnesium levels may appear normal even in cases of underlying intracellular deficiency, although no known mechanism maintains a homeostatic level in the blood other than renal excretion of high blood levels.

Intracellular magnesium is correlated with intracellular potassium. Magnesium is absorbed in the gastrointestinal tract, with more absorbed when status is lower. In humans, magnesium appears to facilitate calcium absorption[citation needed]. Low and high protein intake inhibit magnesium absorption, and other factors such as phosphate, phytate, and fat affect absorption. Absorbed dietary magnesium is largely excreted through the urine, although most magnesium "administered orally" is excreted through the feces.[20] Magnesium status may be assessed roughly through serum and erythrocyte Mg concentrations and urinary and fecal excretion, but intravenous magnesium loading tests are likely the most accurate and practical in most people.[21] In these tests, magnesium is injected intravenously; a retention of 20% or more indicates deficiency.[22] Other nutrient deficiencies are identified through biomarkers, but none are established for magnesium.[23]

Spices, nuts, cereals, coffee, cocoa, tea, and vegetables are rich sources of magnesium. Green leafy vegetables such as spinach are also rich in magnesium as they contain chlorophyll. Observations of reduced dietary magnesium intake in modern Western countries compared to earlier generations may be related to food refining and modern fertilizers that contain no magnesium.[20]

Numerous magnesium dietary supplements are available. Magnesium oxide, one of the most common because it has high magnesium content per weight, has been reported to be the least bioavailable.[24][25] Magnesium citrate has been reported as more bioavailable than oxide or amino-acid chelate (glycinate) forms.[26]

Excess magnesium in the blood is freely filtered at the kidneys, and for this reason it is difficult to overdose on magnesium from dietary sources alone.[19] With supplements, overdose is possible, however, particularly in people with poor renal function; occasionally, with use of high cathartic doses of magnesium salts, severe hypermagnesemia has been reported to occur even without renal dysfunction.[27] Alcoholism can produce a magnesium deficiency, which is easily reversed by oral or parenteral administration, depending on the degree of deficiency.[28]

Detection in biological fluids

Magnesium concentrations in plasma or serum may be measured to monitor for efficacy and safety in those receiving the drug therapeutically, to confirm the diagnosis in potential poisoning victims or to assist in the forensic investigation in a case of fatal overdosage. The newborn children of mothers who received parenteral magnesium sulfate during labor may exhibit toxicity at serum magnesium levels that were considered appropriate for the mothers.[29]

Magnesium in Treatment-resistant Depression

There has been some speculation that magnesium deficiency can lead to depression. Cerebral spinal fluid (CSF) magnesium has been found low in treatment-resistant suicidal depression and in patients that have attempted suicide. Brain magnesium has been found low in TRD using phosphorus nuclear magnetic resonance spectroscopy, an accurate means for measuring brain magnesium. Blood and CSF magnesium do not appear well-correlated with major depression.[30] Magnesium chloride in relatively small doses was found to be as effective in the treatment of depressed elderly type 2 diabetics with hypomagnesemia as imipramine 50 mg daily.[31]

Safety precautions

The magnesium-bodied Honda RA302 of Jo Schlesser crashes and burns during the 1968 French Grand Prix. Schlesser was killed. The magnesium car body did not cause the fire or the death, but it greatly hindered attempts to douse the fire with water.

[citation needed]

Magnesium metal and its alloys are explosive hazards; they are highly flammable in their pure form when molten or in powder or ribbon form. Burning or molten magnesium metal reacts violently with water. When working with powdered magnesium, safety glasses with welding eye protection are employed, because the bright white light produced by burning magnesium contains ultraviolet light that can permanently damage the retinas of the eyes.[32]

Magnesium is capable of reducing water to the highly flammable hydrogen gas:[33]

Mg (s) + 2 H2O (l) → Mg(OH)2 (s) + H2 (g)

As a result, water cannot be used to extinguish magnesium fires; the hydrogen gas produced will only intensify the fire. Dry sand is an effective smothering agent but is usable only on relatively level and flat surfaces.

Magnesium also reacts with carbon dioxide to form magnesium oxide and carbon:

2 Mg (s) + CO2 → 2 MgO (s) + C (s)

Hence, carbon dioxide fire extinguishers cannot be used for extinguishing magnesium fires either.[34]

Burning magnesium is usually quenched by using a Class D dry chemical fire extinguisher, or by covering the fire with sand or magnesium foundry flux to remove its air source.

See Also

References

  1. ^ Bernath, P. F., Black, J. H., & Brault, J. W. (1985). The spectrum of magnesium hydride. 298. p. 375. Bibcode 1985ApJ...298..375B. doi:10.1086/163620 journal= Astrophysical Journal. http://bernath.uwaterloo.ca/media/24.pdf. 
  2. ^ a b (PDF) Abundance and form of the most abundant elements in Earth's continental crust. http://www.gly.uga.edu/railsback/Fundamentals/ElementalAbundanceTableP.pdf. Retrieved 2008-02-15. 
  3. ^ Housecroft, C. E.; Sharpe, A. G. (2008). Inorganic Chemistry (3rd ed.). Prentice Hall. pp. 305–306. ISBN 978-0131755536. 
  4. ^ Ash, Russell (2005). The Top 10 of Everything 2006: The Ultimate Book of Lists. Dk Pub. ISBN 0756613213. http://plymouthlibrary.org/faqelements.htm. 
  5. ^ Anthoni, J Floor (2006). "The chemical composition of seawater". http://www.seafriends.org.nz/oceano/seawater.htm#composition. 
  6. ^ "Magnesium in health". http://www.mg12.info. 
  7. ^ a b Dreizin, Edward L.; Berman, Charles H. and Vicenzi, Edward P. (2000). "Condensed-phase modifications in magnesium particle combustion in air". Scripta Materialia 122: 30–42. doi:10.1016/S0010-2180(00)00101-2. 
  8. ^ DOE Handbook – Primer on Spontaneous Heating and Pyrophoricity. U.S. Department of Energy. December 1994. p. 20. DOE-HDBK-1081-94. http://www.hss.doe.gov/nuclearsafety/ns/techstds/standard/hdbk1081/hbk1081c.html. 
  9. ^ "Minerals Information". USGS. http://minerals.usgs.gov/minerals/index.html. Retrieved 2011-01-04. 
  10. ^ Vardi, Nathan (February 22, 2007). "Man With Many Enemies". Forbes.com. http://www.forbes.com/forbes/2002/0722/044_print.html. Retrieved 2006-06-26. 
  11. ^ Davy, H. (1808) "Electro-chemical researches on the decomposition of the earths; with observations on the metals obtained from the alkaline earths, and on the amalgam procured from ammonia," Philosophical Transactions of the Royal Society of London, vol. 98, pages 333–370.
  12. ^ "Magnesium Video – The Periodic Table of Videos – University of Nottingham". http://www.periodicvideos.com/videos/012.htm. Retrieved 2011-02-23. 
  13. ^ a b Baker, Hugh D. R.; Avedesian, Michael (1999). Magnesium and magnesium alloys. Materials Park, OH: Materials Information Society. p. 4. ISBN 0-87170-657-1. 
  14. ^ Ketil Amundsen, Terje Kr. Aune, Per Bakke, Hans R. Eklund, Johanna Ö. Haagensen, Carlos Nicolas, Christian Rosenkilde, Sia Van den Bremt, Oddmund Wallevik “Magnesium” in Ullmann’s Encyclopedia of Industrial Chemistry, 2002, Wiley-VCH. doi: 10.1002/14356007.a15_559
  15. ^ Luo, Alan A. and Powell, Bob R. (2001) (PDF). Tensile and Compressive Creep of Magnesium-Aluminum-Calcium Based Alloys. Materials & Processes Laboratory, General Motors Research & Development Center. Archived from the original on 2007-09-28. http://web.archive.org/web/20070928023445/http://doc.tms.org/ezmerchant/prodtms.nsf/productlookupitemid/01-481x-137/$FILE/01-481X-137F.pdf. Retrieved 2007-08-21. 
  16. ^ Ravi Kumar, N. V. (2003). "Effect of alloying elements on the ignition resistance of magnesium alloys". Scripta Materialia 49 (3): 225–230. doi:10.1016/S1359-6462(03)00263-X. 
  17. ^ "Magnesium". Ods.od.nih.gov. 2009-07-13. http://ods.od.nih.gov/factsheets/magnesium. Retrieved 2011-11-04. 
  18. ^ "Lack Energy? Maybe It's Your Magnesium Level". United States Department of Agriculture. http://www.ars.usda.gov/is/AR/archive/may04/energy0504.htm?pf=1. Retrieved 2008-09-18.  Last paragraph
  19. ^ a b University of Maryland Medical Center. Magnesium
  20. ^ a b Wester PO (1987). "Magnesium". Am. J. Clin. Nutr. 45 (5 Suppl): 1305–12. PMID 3578120. 
  21. ^ Arnaud MJ (2008). "Update on the assessment of magnesium status". Br. J. Nutr. 99 Suppl 3: S24–36. doi:10.1017/S000711450800682X. PMID 18598586. 
  22. ^ Rob PM, Dick K, Bley N et al. (1999). "Can one really measure magnesium deficiency using the short-term magnesium loading test?". J. Intern. Med. 246 (4): 373–378. doi:10.1046/j.1365-2796.1999.00580.x. PMID 10583708. 
  23. ^ Franz KB (2004). "A functional biological marker is needed for diagnosing magnesium deficiency". J Am Coll Nutr 23 (6): 738S–41S. PMID 15637224. 
  24. ^ Firoz M, Graber M (2001). "Bioavailability of US commercial magnesium preparations". Magnes Res 14 (4): 257–62. PMID 11794633. 
  25. ^ Lindberg JS, Zobitz MM, Poindexter JR, Pak CY (1990). "Magnesium bioavailability from magnesium citrate and magnesium oxide". J Am Coll Nutr 9 (1): 48–55. PMID 2407766. 
  26. ^ Walker AF, Marakis G, Christie S, Byng M (2003). "Mg citrate found more bioavailable than other Mg preparations in a randomised, double-blind study". Magnes Res 16 (3): 183–91. PMID 14596323. http://www.john-libbey-eurotext.fr/medline.md?issn=0953-1424&vol=16&iss=3&page=183. 
  27. ^ Kontani M, Hara A, Ohta S, Ikeda T (2005). "Hypermagnesemia induced by massive cathartic ingestion in an elderly woman without pre-existing renal dysfunction". Intern. Med. 44 (5): 448–452. doi:10.2169/internalmedicine.44.448. PMID 15942092. 
  28. ^ Giannini, A. J. (1997). Drugs of Abuse (Second ed.). Los Angeles: Physicians Management Information Co.. ISBN 0874894999. 
  29. ^ R. Baselt, Disposition of Toxic Drugs and Chemicals in Man, 8th edition, Biomedical Publications, Foster City, CA, 2008, ISBN 0962652377 pp. 875–877.
  30. ^ Eby Ga, 3rd; Eby, KL (2010). "Magnesium for treatment-resistant depression: a review and hypothesis". Medical hypotheses 74 (4): 649–660. doi:10.1016/j.mehy.2009.10.051. PMID 19944540. http://george-eby-research.com/html/magnesium-treatment-resistant-depression.pdf. 
  31. ^ Barragán-Rodríguez, L; Rodríguez-Morán, M; Guerrero-Romero, F (2008). "Efficacy and safety of oral magnesium supplementation in the treatment of depression in the elderly with type 2 diabetes: a randomized, equivalent trial". Magnesium research : official organ of the International Society for the Development of Research on Magnesium 21 (4): 218–23. PMID 19271419. 
  32. ^ "Science Safety: Chapter 8". Government of Manitoba. http://www.edu.gov.mb.ca/k12/docs/support/scisafe/chapter8.html. Retrieved 2007-08-21. 
  33. ^ "Chemistry : Periodic Table : magnesium : chemical reaction data". webelements.com. http://www.webelements.com/webelements/elements/text/Mg/chem.html. Retrieved 2006-06-26. 
  34. ^ "Demo Lab: Reaction Of Magnesium Metal With Carbon Dioxide". http://www.ilpi.com/genchem/demo/co2mg/. Retrieved 2006-06-26. 

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  • Magnesium — Mag*ne si*um, n. [NL. & F. See {Magnesia}.] (Chem.) A light silver white metallic element of atomic number 12, malleable and ductile, quite permanent in dry air but tarnishing in moist air. It burns, forming (the oxide) magnesia, with the… …   The Collaborative International Dictionary of English

  • Magnesium [1] — Magnesium Mg, Metall. Atomgew. 24,36, spez. Gew. 1,75; Schmelzpunkt 633°, Siedepunkt 1100°. Das silberweiße duktile und hämmerbare Metall entzündet sich bei höherer Temperatur und verbrennt mit intensiv weißem Lichte zu Magnesia. Es zersetzt… …   Lexikon der gesamten Technik

  • Magnesium [2] — Magnesium, Mg, Metall. Atomgew. 24,32, spez. Gew. 1,75, Schmelzpunkt 650°, Siedepunkt 1120°. Magnesium ist ein wertvoller Zusatz (etwa 1/2%) zu Aluminium und bildet mit ihm die Legierung Magnalium (s.d., Bd. 6, S. 275) sowie Kupfer oder Zink… …   Lexikon der gesamten Technik

  • Magnesium — Magnesĭum, Magnium, Talzium (chem. Zeichen Mg), metallisches Element, in der Natur weit verbreitet, aber nicht frei, sondern nur in Salzen (Magnesit, Dolomit, Olivin, Talk, Speckstein, Serpentin, Meerschaum, in den Abraumsalzen …   Kleines Konversations-Lexikon

  • Magnesium — (griech.) Chemisches Element, das silbrig glänzende, sehr reaktionsfähige Metall verbrennt mit blendend weißem Licht zu Magnesiumoxyd. Auf Grund dieser Eigenschaft fand es Verwendung als Blitzlicht. Bis zur Mitte des 20. Jahrhunderts wurde es zu… …   Das Lexikon aus „Bernie's Foto-Programm"

  • Magnesĭum — (Magnium, Talcium), chemisches Zeichen: Mg, Atomgewicht = 158 (O = 100) od. 12 (H = 1) das metallische Radical der Magnesia (Bittererde, Talkerde). Man erhält es, indem man Kalium in einer unten zugeschmolzenen Röhre von hartem Glas, od. in einem …   Pierer's Universal-Lexikon

  • Magnesium — Magnesium, alter Name des Mangans (s. d.) …   Meyers Großes Konversations-Lexikon

  • Magnesĭum — Mg, Metall, findet sich nicht gediegen, aber sehr verbreitet in verschiedenen Verbindungen. Magnesiumoxyd (Magnesia) bildet mit Tonerde den Spinell; kieselsaure Magnesia bildet den Meerschaum, Talk, Speckstein, Serpentin und findet sich auch im… …   Meyers Großes Konversations-Lexikon

  • Magnesium — Magnesium, Magnium, Talcium, ein aus der Magnesia (M.oxyd), zuerst von H. Davy, sodann von Bussy noch vollständiger dargestelltes, silberweißes, lebhaft glänzendes, sehr dehnbares Metall. Es krystallisirt nach Becquerel in Octaëdern. Vgl.… …   Herders Conversations-Lexikon


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