Magnesium
MAGNESIUM
Physical Science Research Paper
General Information
Symbol: Mg
Atomic Number: 12
Atomic Mass: 24.305 amu
Melting Point: 650 °C (1202 °F)
Boiling Point: 1107 °C (2024 °F)
Classification: Alkaline Earth
Density: 1.938 g/cm3
Color: grayish
Crystal Structure: Hexagonal
Date of Discovery: 1808
Discoverer: Sir Humphrey Davy
Mostly Obtained From: Seawater
No. of Energy Levels: 3
No. of Protons/Electrons: 12
No. of Neutrons: 12
First Energy Level: 2
Second Energy Level: 8
Third Energy Level: 2
Isotope
Half-Life
Mg-24
Stable
Mg-25
Stable
Mg-26
Stable
Mg-27
9min 25sec
Mg-28
21 hours
Basic Information
Magnesium, a silvery white metal that is in appearance similar to aluminum, is the eight most
abundant element in the Earth's crust (about 2.5 percent). Its density of only two thirds of aluminum's is
making it the lightest structural metal known, however in its pure form it lacks sufficient strength for most
structural application.
At high temperatures (650 °C; 1190 °F) is strongly reactive with oxygen, and in dry air it burns
with bright white light and intense heat.
Magnesium is about one-sixth as plentiful as potassium in human body cells, however it is
required as a catalyst for enzyme reactions in carbohydrate metabolism. Lack of magnesium can produce severe
health problems like kidney disease, weakness and dizziness.
Also in nature, it does not occur in its free form. It was known in compounds and was first
isolated in 1808 by Sir Humphrey Davis, who evaporated the mercury from a magnesium amalgam made by
electrolyzing a mixture of moist magnesia and mercuric oxide.
Occurrence and uses
Magnesium is usually distributed in minerals such as magnesite, dolomite, burcite, serpentine,
chrysolite, meerschaum, talc, and most kinds of asbestos. Also seawater contains about 0.13 percent
magnesium, mostly as the dissolved chloride.
Therefore is now commercially produced by electrolysis of molten magnesium chloride (MgCl2),
obtained from seawater by reducing of its compounds by with suitable reducing agents.
Its low structural strength is preventing it to be used in pure form, but the addition of alloying
elements improves the strength to such an extent that it is widely used mostly in the aerospace industry, other
machinery, automotive industry and even home appliances. A part that would weight 32 pounds when made of
steel weights only 7 pounds when made from magnesium alloys.
At room temperature a stable film of water insoluble magnesium hydroxide forms on the metal's
surface, protecting it from corrosion in most atmospheres.
Because it is strongly reactive and it forms stable compounds, it is also being used in metallurgy
processes like production of titanium from titanium tetrachloride and defluorization of blast-furnace iron. The
capability of fast burning caused it to be used for photographic flash ribbon, incendiary bombs. Today it is still
used in pyrotechnics.
Compounds
Magnesium oxide, MgO, commonly called magnesia, a white solid capable of withstanding extreme heats.
Therefore is used in the manufacture electrical and thermal insulators, high-temperature refractory
bricks and also cements, fertilizers, rubber, plastic, and as laxative.
Magnesium chloride, MgCl2, a color less, water-absorbing substance. Most of its uses are in magnesium metal
production, manufacturing of cement flooring, and in textile manufacturing.
Magnesium carbonate, MgCO3, in nature called magnesite, the odor less white powder or stone has many
uses. The natural form is a source of elemental magnesium. Otherwise it is used as heat insulator, food
additive, or in cosmetics, pharmaceuticals, rubbers, inks, and glass.
Magnesium hydroxide, Mg(OH)2, a white powder produced from sea water by addition of milk of lime. It is a
primary raw material for magnesium metal production.
Magnesium sulfate, MgSO4, synthetically prepared is sold as Epson Salt, a colorless, crystalline substance
formed by reaction of magnesium hydroxide with sulfur dioxide and air. Used in cement and fertilizers
manufacturing, tanning and dyeing, or as a purgative.
Hydrate from magnesium sulfate, MgSO4H2O, occurs as a mineral deposit.
Grignard reagents, an organometallic compound, composed of an organic group, a halogen other than
fluorine, and magnesium. In nature it is a constituent of chlorophyll. In industry it is used in the
production of other organometallic compounds.
Sources
? Bentor, Yinon, Chemical Elements
http://www.chemicalelemen ts.com ? Encyclopedia Britannica
http://www.britanica.com ? Martin Marietta Materials
http://magnesite.com