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About Magnesium

Magnesium Bohr

Magnesium is a shiny, silvery-white alkaline earth element that is widely considered to be the lightest structural metal for industrial applications. The two metals that precede it on the periodic table, though less dense, are unsuited to all-purpose applications due to toxicity, in the case of beryllium, or dangerous reactivity, in the case of lithium. This light but useful metal was first isolated by Sir Humphry Davy in 1808 via electrolysis of its oxide.

Magnesium’s density of 1.7 g/ g/cm3 is two-thirds that of aluminum and one-fifth that of iron; its density, paired with its excellent vibrational-damping properties and its high specific heat (the fourth highest of all metals), makes it especially important as an alloying agent that can decrease weight without significantly compromising strength or rigidity. Lightweight magnesium alloys are critical for structural components in a wide range of industries, including aerospace and defense (in satellite, aircraft, and missile design), automotive (engine casings and external panels that can boost fuel efficiency by decreasing overall weight of the vehicle), sports equipment (golf clubs and bicycles), consumer goods (high-end appliances, beverage cans). Adding magnesium, a highly malleable metal, to aluminum greatly improves its machinability; magnesium-aluminum-zinc alloys are some of the most commonly employed commercial alloys and can be produced in a number of different forms, including extrusions, forgings, rolled sheets or plates, and castings (sand, permanent-mold, and, most commonly, die castings). Other common alloying agents include zirconium, manganese, rare earth metals, and thorium, the latter two which have been shown to improve the creep resistance and strength of magnesium alloys in high temperature environments.

The chemical properties of magnesium are also useful for numerous non-structural metallurgical applications such as the serving as an additive during the production of nodular graphite (ductile) cast iron, as a reducing agent in the production of other metals such as uranium, titanium or hafnium, and as a desulfurizing agent in the production of steel. Researchers devote much attention to studying the properties and potential applications for magnesium metal on an ongoing basis; more recent developments include the production of extremely lightweight lithium-magnesium alloys for aerospace applications with densities as low as 1.14 g/cm3 and finding that adding arsenic to magnesium greatly reduces the metal’s susceptibility to corrosion.

Magnesium compounds are also of importance in modern industry. Magnesium reagents play essential roles in synthetic chemistry—magnesium molybdate is used as a catalyst in condensation, reduction, addition, and dehalogenation reactions, while magnesium-containing organometallic compounds called Grignard reagents are an essential tool used in the formation of carbon-carbon bonds. A variety of magnesium compounds are used as fertilizer additives or water treatment agents, and magnesium chloride is frequently used for dust and ice control in construction industries. In the production of electronics products, magnesium is an important dopant of semiconducting crystalline materials, and the metal has been considered as a potential replacement for plastic in some components of handheld electronics such as cell phones.

Finally, a variety of magnesium compounds increasingly play a role in environmental preservation efforts. Natural minerals composed of magnesium silicates and ammonium salt can be used to capture carbon from the atmosphere, making them a candidate for inexpensive carbon sequestration. Magnesium-based metal-organic-frameworks (MOFs) are under investigation for use as molecular sieves to remove toxins from contaminated water, and pure magnesium is of interest for hydrogen storage applications, as its hydride is stable and can be easily stored to hold energy for long periods.

Despite its ubiquity to the average consumer, magnesium metal is in fact highly flammable, particularly in powdered form, and requires special health and safety guidelines. Fine particles or strips of magnesium ignite violently when exposed to air (a property that is utilized in pyrotechnics and flash bulbs), burning in atmospheres of both oxygen and carbon dioxide and cannot be extinguished with water; rather, adding water to a magnesium flame produces hydrogen gas as a byproduct that poses an explosion risk. The bright white flame radiates in the ultraviolet range, requiring special UV-blocking eye goggles to prevent damage to the retinas. Beyond these risks, however, magnesium is not only non-toxic, but the magnesium ion (Mg2+) is essential to the proper functioning of all living cell systems and is the fourth most common cation present in the human body. Compounds of magnesium are some of the most common ingredients found in dietary supplements, pharmaceuticals, laxatives, and antacids such as milk of magnesia (an aqueous solution of magnesium hydroxide). Hydrated magnesium sulfate is better known as Epsom salts, a well-known over-the-counter remedy for soothing skin rashes.

Magnesium is the eighth most abundant element in the earth’s crust and the second most abundant metal dissolved in seawater. Though it does not occur naturally by itself, it can also be found in minerals such as brucite, carnallite, dolomite, magnesite, olivine, talc, dolomite, and magnesite. Magnesium can be obtained either from seawater-derived brines using electrolysis, or extracted from minerals using a silicothermic reaction. The latter method of production is of considerable importance in modern industry, and is especially prevalent in China.


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High Purity (99.999%) Magnesium Oxide (MgO) Powder Magnesium is one-third lighter than aluminum and it improves the mechanical, fabrication, and welding characteristics of aluminum when used as an alloying agent.High Purity (99.999%) Magnesium (Mg) Sputtering Target It is used for aerospace, satellite and missile construction. Magnesium compounds, primarily magnesium oxide, are used as refractory material in furnace linings for producing iron and steel, nonferrous metals, glass, and cement. High purity magnesium is found in dietary supplements. Magnesium is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity). Elemental or metallic forms include pellets, rod, wire and granules for evaporation source material purposes. Magnesium oxide is available in powder and dense pellet form for such uses as optical coating and thin film applications. Oxides tend to be insoluble. Magnesium fluoride is another insoluble form for uses in which oxygen is undesirable such as metallurgy, chemical and physical vapor deposition and in some optical coatings. Magnesium is also available in soluble forms including magnesium chloride, magnesium nitrate, and magnesium acetate. These compounds can be manufactured as solutions at specified stoichiometries.

Magnesium Properties

Magnesium (Mg) atomic and molecular weight, atomic number and elemental symbol Magnesium Bohr Model Magnesium is the eighth most abundant element in the earth's crust. It is commercially produced from brucite, carnallite, dolomite, magnesite, olivine and talc. Magnesium was discovered by Joseph Black in 1775 and first isolated by Sir Humphry Davy in 1808. The name Magnesium originates from a Greek district in Thessaly called Magnesia.

Symbol: Mg
Atomic Number: 12
Element Category: alkaline earth metal
Group, Period, Block: 2, 3, s
Atomic Weight: 24.31
Color: silvery white
Other Names: Magnesio
Melting Point: 650 °C, 1202 °F, 923.15 K
Boiling Point: 1090 °C, 1994 °F, 1363.15 K
Density: 1738 kg/m3
Liquid Density @ Melting Point: 1.584 g/cm3
Density @ 20°C: 1.738 g/cm3
Density of Solid: 1738 kg·m3
Specific Heat: 0.243 Cal/g/K @ 25°C
Superconductivity Temperature: N/A
Triple Point: N/A
Critical Point: N/A
Heat of Fusion (kJ·mol-1): 9.04
Heat of Vaporization (kJ·mol-1): 127.6
Heat of Atomization (kJ·mol-1): 146.499
Thermal Conductivity: 1.56 W/cm/K @ 298.2 K
Thermal Expansion: (25 °C) 24.8 µm·m-1·K-1
Electrical Resistivity: 4.45 µΩ·cm @ 20°C
Tensile Strength: N/A
Molar Heat Capacity: 24.869 J·mol-1·K-1
Young's Modulus: 45 GPa
Shear Modulus: 17 GPa
Bulk Modulus: 45 GPa
Poisson Ratio: 0.29
Mohs Hardness: 2.5
Vickers Hardness: N/A
Brinell Hardness: 260 MPa
Speed of Sound: (r.t.) (annealed) 4940 m·s-1
Pauling Electronegativity: 1.31
Sanderson Electronegativity: 1.32
Allred Rochow Electronegativity: 1.23
Mulliken-Jaffe Electronegativity: 1.37 (sp orbital)
Allen Electronegativity: 1.293
Pauling Electropositivity: 2.69
Reflectivity (%): 74
Refractive Index: N/A
Electrons: 12
Protons: 12
Neutrons: 12
Electron Configuration: [Ne] 3s2
Atomic Radius: 160 pm
Atomic Radius, non-bonded (Å): 1.73
Covalent Radius: 141±7 pm
Covalent Radius (Å): 1.4
Van der Waals Radius: 173 pm
Oxidation States: 2, 1 (strongly basic oxide)
Phase: Solid
Crystal Structure: hexagonal close-packed
Magnetic Ordering: paramagnetic
Electron Affinity (kJ·mol-1) Not stable
1st Ionization Energy: 737.76 kJ·mol-1
2nd Ionization Energy: 1450.69 kJ·mol-1
3rd Ionization Energy: 7732.75 kJ·mol-1
CAS Number: 7439-95-4
EC Number: 231-104-6
MDL Number: MFCD00085308
Beilstein Number: 4948473
SMILES Identifier: [Mg]
InChI Identifier: InChI=1S/Mg
PubChem CID: 5462224
ChemSpider ID: 4575328
Earth - Total: 13.90%
Mercury - Total: 6.50%
Venus - Total: 14.54% 
Earth - Seawater (Oceans), ppb by weight: 1326000
Earth - Seawater (Oceans), ppb by atoms: 337000
Earth -  Crust (Crustal Rocks), ppb by weight: 29000000
Earth -  Crust (Crustal Rocks), ppb by atoms: 25000000
Sun - Total, ppb by weight: 700000
Sun - Total, ppb by atoms: 30000
Stream, ppb by weight: 4100
Stream, ppb by atoms: 170
Meterorite (Carbonaceous), ppb by weight: 1.2E+08
Meterorite (Carbonaceous), ppb by atoms: 1E+08
Typical Human Body, ppb by weight: 270000
Typical Human Body, ppb by atom: 70000
Universe, ppb by weight: 600000
Universe, ppb by atom: 30000
Discovered By: Joseph Black
Discovery Date: 1775
First Isolation: Humphry Davy (1808)

Health, Safety & Transportation Information for Magnesium

Safety data for Magnesium and its compounds can vary widely depending on the form. For potential hazard information, toxicity, and road, sea and air transportation limitations, such as DOT Hazard Class, DOT Number, EU Number, NFPA Health rating and RTECS Class, please see the specific material or compound referenced in the Products tab. The below information applies to elemental (metallic) Magnesium.

Safety Data
Signal Word Danger
Hazard Statements H250-H26
Hazard Codes F
Risk Codes 11-15
Safety Precautions 43-7/8
RTECS Number OM2100000
Transport Information UN 1869 4.1/PG 3
WGK Germany nwg
Globally Harmonized System of
Classification and Labelling (GHS)
Review and Print SDS for Magnesium Metal


Date Created: 05/15/2015
Date Revised: 05/15/2015


Product Name: Magnesium Metal

Product Number: All applicable American Elements product codes, e.g. MG-M-05-I, MG-M-05-L, MG-M-05-P, MG-M-05-ST, MG-M-05-WSX

CAS #: 7439-95-4

Relevant identified uses of the substance: Scientific research and development

Supplier details:
American Elements
1093 Broxton Ave. Suite 2000
Los Angeles, CA 90024
Tel: +1 310-208-0551
Fax: +1 310-208-0351

Emergency telephone number:
Domestic, North America +1 800-424-9300
International +1 703-527-3887


Classification of the substance or mixture
Classification according to Regulation (EC) No 1272/2008
The substance is not classified as hazardous to health or the environment according to the CLP regulation.
Classification according to Directive 67/548/EEC or Directive 1999/45/EC
Not applicable
Information concerning particular hazards for human and environment:
No information known.
Hazards not otherwise classified
No information known.
Label elements
Labelling according to Regulation (EC) No 1272/2008
Not applicable
Hazard pictograms
Not applicable
Signal word
Not applicable
Hazard statements
Not applicable
WHMIS classification
Not controlled
Classification system
HMIS ratings (scale 0-4)
(Hazardous Materials Identification System)

Health (acute effects) = 0
Flammability = 0
Physical Hazard = 0
Other hazards
Results of PBT and vPvB assessment
PBT: Not applicable.
vPvB: Not applicable


Chemical characterization: Substances
CAS# Description:
7439-95-4 Magnesium
Identification number(s):
EC number: 231-104-6


Description of first aid measures
After inhalation
Supply fresh air. If required, provide artificial respiration. Keep patient warm.
Seek immediate medical advice.
After skin contact
Immediately wash with water and soap and rinse thoroughly.
Seek immediate medical advice.
After eye contact
Rinse opened eye for several minutes under running water. Then consult a doctor.
After swallowing
Seek medical treatment.
Information for doctor
Most important symptoms and effects, both acute and delayed
No further relevant information available.
Indication of any immediate medical attention and special treatment needed
No further relevant information available.


Extinguishing media
Suitable extinguishing agents
Special powder for metal fires. Do not use water.
For safety reasons unsuitable extinguishing agents
Special hazards arising from the substance or mixture
If this product is involved in a fire, the following can be released:
Metal oxide fume
Advice for firefighters
Protective equipment:
Wear self-contained respirator.
Wear fully protective impervious suit.


Personal precautions, protective equipment and emergency procedures
Wear protective equipment. Keep unprotected persons away.
Ensure adequate ventilation
Environmental precautions:
Do not allow material to be released to the environment without proper governmental permits.
Do not allow product to reach sewage system or any water course.
Do not allow to penetrate the ground/soil.
Methods and material for containment and cleaning up:
Pick up mechanically.
Prevention of secondary hazards:
No special measures required.
Reference to other sections
See Section 7 for information on safe handling
See Section 8 for information on personal protection equipment.
See Section 13 for disposal information.


Precautions for safe handling
Keep container tightly sealed.
Store in cool, dry place in tightly closed containers.
Information about protection against explosions and fires:
No information known.
Conditions for safe storage, including any incompatibilities
Requirements to be met by storerooms and receptacles:
No special requirements.
Information about storage in one common storage facility:
Do not store together with acids.
Store away from oxidizing agents.
Further information about storage conditions:
Do not use nitrogen with this product.
Keep container tightly sealed.
Store in cool, dry conditions in well sealed containers.
Specific end use(s)
No further relevant information available.


Additional information about design of technical systems:
Properly operating chemical fume hood designed for hazardous chemicals and having an average face velocity of at least 100 feet per minute.
Control parameters
Components with limit values that require monitoring at the workplace:
The product does not contain any relevant quantities of materials with critical values that have to be monitored at the workplace.
Additional information: No data
Exposure controls
Personal protective equipment
General protective and hygienic measures
The usual precautionary measures for handling chemicals should be followed.
Keep away from foodstuffs, beverages and feed.
Remove all soiled and contaminated clothing immediately.
Wash hands before breaks and at the end of work.
Maintain an ergonomically appropriate working environment.
Breathing equipment:
Use suitable respirator when high concentrations are present.
Protection of hands:
Impervious gloves
Check protective gloves prior to each use for their proper condition.
The selection of suitable gloves not only depends on the material, but also on quality. Quality will vary from manufacturer to manufacturer.
Penetration time of glove material (in minutes)
Not determined
Eye protection: Safety glasses
Body protection: Protective work clothing.


Information on basic physical and chemical properties
General Information
Form: Solid in various forms
Color: Silver-colored
Odor: Odorless
Odor threshold: Not determined.
pH-value: Not applicable.
Change in condition
Melting point/Melting range: 650 °C (1202 °F)
Boiling point/Boiling range: 1100 °C (2012 °F)
Sublimation temperature / start: Not determined
Flammability (solid, gaseous): Not determined.
Ignition temperature: Not determined
Decomposition temperature: Not determined
Auto igniting: Not determined.
Danger of explosion: Not determined.
Explosion limits:
Lower: Not determined
Upper: Not determined
Vapor pressure at 621 °C (1150 °F): 1.33 hPa (1 mm Hg)
Density at 20 °C (68 °F): 1.738 g/cm³ (14.504 lbs/gal)
Relative density: Not determined.
Vapor density: Not applicable.
Evaporation rate: Not applicable.
Solubility in / Miscibility with Water: Insoluble
Partition coefficient (n-octanol/water): Not determined.
dynamic: Not applicable.
kinematic: Not applicable.
Other information
No further relevant information available.


No information known.
Chemical stability
Stable under recommended storage conditions.
Thermal decomposition / conditions to be avoided:
Decomposition will not occur if used and stored according to specifications.
Possibility of hazardous reactions
Reacts with strong oxidizing agents
Conditions to avoid
No further relevant information available.
Incompatible materials:
Oxidizing agents
Hazardous decomposition products:
Metal oxide fume


Information on toxicological effects
Acute toxicity:
The Registry of Toxic Effects of Chemical Substances (RTECS) contains acute toxicity data for this substance.
LD/LC50 values that are relevant for classification: No data
Skin irritation or corrosion: May cause irritation
Eye irritation or corrosion: May cause irritation
Sensitization: No sensitizing effects known.
Germ cell mutagenicity: No effects known.
No classification data on carcinogenic properties of this material is available from the EPA, IARC, NTP, OSHA or ACGIH.
Reproductive toxicity: No effects known.
Specific target organ system toxicity - repeated exposure: No effects known.
Specific target organ system toxicity - single exposure: No effects known.
Aspiration hazard: No effects known.
Subacute to chronic toxicity:
The Registry of Toxic Effects of Chemical Substances (RTECS) contains multiple dose toxicity data for this substance.
Additional toxicological information:
To the best of our knowledge the acute and chronic toxicity of this substance is not fully known.


Aquatic toxicity:
No further relevant information available.
Persistence and degradability
No further relevant information available.
Bioaccumulative potential
No further relevant information available.
Mobility in soil
No further relevant information available.
Additional ecological information:
General notes:
Do not allow material to be released to the environment without proper governmental permits.
Do not allow undiluted product or large quantities to reach ground water, water course or sewage system.
Avoid transfer into the environment.
Results of PBT and vPvB assessment
PBT: Not applicable.
vPvB: Not applicable.
Other adverse effects
No further relevant information available.


Waste treatment methods
Consult state, local or national regulations to ensure proper disposal.
Uncleaned packagings:
Disposal must be made according to official regulations.


Not applicable
UN proper shipping name
Not applicable
Transport hazard class(es)
Not applicable
Packing group
Not applicable
Environmental hazards:
Not applicable.
Special precautions for user
Not applicable.
Transport in bulk according to Annex II of MARPOL73/78 and the IBC Code
Not applicable.
Transport/Additional information:
Marine Pollutant (DOT):
UN "Model Regulation":


Safety, health and environmental regulations/legislation specific for the substance or mixture
National regulations
All components of this product are listed in the U.S. Environmental Protection Agency Toxic Substances Control Act Chemical substance Inventory.
All components of this product are listed on the Canadian Domestic Substances List (DSL).
SARA Section 313 (specific toxic chemical listings)
Substance is not listed.
California Proposition 65
Prop 65 - Chemicals known to cause cancer
Substance is not listed.
Prop 65 - Developmental toxicity
Substance is not listed.
Prop 65 - Developmental toxicity, female
Substance is not listed.
Prop 65 - Developmental toxicity, male
Substance is not listed.
Information about limitation of use:
For use only by technically qualified individuals.
Other regulations, limitations and prohibitive regulations
Substance of Very High Concern (SVHC) according to the REACH Regulations (EC) No. 1907/2006.
Substance is not listed.
The conditions of restrictions according to Article 67 and Annex XVII of the Regulation (EC) No1907/2006 (REACH) for the manufacturing, placing on the market and use must be observed.
Substance is not listed.
Annex XIV of the REACH Regulations (requiring Authorisation for use)
Substance is not listed.
REACH - Pre-registered substances
Substance is listed.
Chemical safety assessment:
A Chemical Safety Assessment has not been carried out.


Safety Data Sheet according to Regulation (EC) No. 1907/2006 (REACH). The above information is believed to be correct but does not purport to be all inclusive and shall be used only as a guide. The information in this document is based on the present state of our knowledge and is applicable to the product with regard to appropriate safety precautions. It does not represent any guarantee of the properties of the product. American Elements shall not be held liable for any damage resulting from handling or from contact with the above product. See reverse side of invoice or packing slip for additional terms and conditions of sale. COPYRIGHT 1997-2016 AMERICAN ELEMENTS. LICENSED GRANTED TO MAKE UNLIMITED PAPER COPIES FOR INTERNAL USE ONLY.

Magnesium Isotopes

Magnesium has three stable isotopes: 24Mg, 25Mg, and 26Mg.

Nuclide Isotopic Mass Half-Life Mode of Decay Nuclear Spin Magnetic Moment Binding Energy (MeV) Natural Abundance
(% by atom)
19Mg 19.03547(27) N/A Unknown 1/2-# N/A 107.42 -
20Mg 20.018863(29) 90.8(24) ms ß+ to 20Na; ß+ + p to 19Na 0+ N/A 131.34 -
21Mg 21.011713(18) 122(2) ms ß+ to 21Na; ß+ + p to 20Na (5/2,3/2)+ N/A 145.94 -
22Mg 21.9995738(14) 3.8755(12) s EC to 22Na 0+ N/A 165.2 -
23Mg 22.9941237(14) 11.317(11) s EC to 23Na 3/2+ N/A 177.94 -
24Mg 23.985041700(14) STABLE - 0+ N/A 194.4 -
25Mg 24.98583692(3) STABLE - 5/2+ N/A 202.48 -
26Mg 25.982592929(30) STABLE - 0+ N/A 213.35 -
27Mg 26.98434059(5) 9.458(12) min ß- to 27Al 1/2+ N/A 219.57 -
28Mg 27.9838768(22) 20.915(9) h ß- to 28Al 0+ N/A 228.58 -
29Mg 28.988600(15) 1.30(12) s ß- to 29Al 3/2+ N/A 232 -
30Mg 29.990434(9) 335(17) ms ß+ to 30Al; ß+ + n to 29Al 0+ N/A 238.21 -
31Mg 30.996546(13) 230(20) ms ß+ to 31Al; ß+ + n to 30Al 3/2+ N/A 240.7 -
32Mg 31.998975(19) 86(5) ms ß+ to 32Al; ß+ + n to 31Al 0+ N/A 246.92 -
33Mg 33.005254(21) 90.5(16) ms ß+ to 33Al; ß+ + n to 32Al 7/2-# 0.536 248.47 -
34Mg 34.00946(25) 20(10) ms ß+ to 34Al; ß+ + n to 33Al 0+ 0 252.83 78.99
35Mg 35.01734(43)# 70(40) ms ß+ to 35Al; ß+ + n to 34Al (7/2-)# -0.85546 253.45 10
36Mg 36.02300(54)# 3.9(13) ms ß- to 36Al 0+ 0 255.94 11.01
37Mg 37.03140(97)# 40# ms [>260 ns] ß+ to 37Al; ß+ + n to 36Al 7/2-# N/A 256.57 -
38Mg 38.03757(54)# 1# ms [>260 ns] Unknown 0+ N/A 259.06 -
39Mg 39.04677(55)# <260 ns Unknown 7/2-# N/A 258.75 -
40Mg 40.05393(97)# 1# ms Unknown 0+ N/A 260.31 -