Free Science Tutorial on the Chemistry of Magnesium

Magnesium is an alkaline earth metal and is having a variety of applications in various fields. It belongs to group 2A of the periodic table. It is a very reactive metal and is not available in its metallic form, The chemistry of this metal is discussed in this article.


Magnesium is a metallic element and the third most abundant metal in the Earth's crust. There are almost 60 known ores for magnesium. This metal is found in seawater and underground. But magnesium as metal is not found in the universe. It is to be obtained by processing the ores of magnesium. It is a shiny, silvery coloured metal and the known lightest metal.

Magnesium was not identified as a separate metal till 1755. The difference between magnesium and calcium was not known at that time. Joseph Black. A Scottish scientist distinguished the two elements from each other. Sir Humphrey Davy isolated magnesium in 1808 from a magnesium-mercury amalgam. It is an alkaline earth metal belonging to group 2 of the periodic table. The symbol of Magnesium is Mg.

Magnesium Properties:

Some of the physical and chemical properties are discussed below.
  1. The melting point of magnesium is : 650^0C

  2. The boiling point is 1090^0c

  3. The magnesium is having a density of 1.74g/cm3

  4. Magnesium atomic weight is 24.305

  5. Atomic number of this metal is 12

  6. Electronegativity of magnesium is 1.31

  7. Magnesium burns in the open air. It reacts with oxygen and produces a brilliant white flame. In this reaction magnesium oxide(MgO) is the product obtained. This magnesium oxide reacts with hydrogen peroxide to form magnesium peroxide (MgO2)

  8. Magnesium is having a tendency to react slowly with hot water and very fast with steam to form magnesium hydroxide{Mg(OH)2}and magnesium oxide respectively.

  9. Magnesium hydroxide reacts with sulphur dioxide and oxygen to form magnesium sulfate. This is having many uses in health care products manufacture.

  10. Magnesium carbonate will be formed by the reaction of magnesium oxide with carbon dioxide. This is an antacid and finds a variety of applications in the health care industry.

  11. Magnesium phosphate, Mg3(PO4)2 is a combination of magnesium and Phosphorous. It is widely used in the baking industry. It is also a fire retardant and coated on wood to make it fireproof. It is a dietary supplement and is very useful for increasing bone strength.

  12. Magnesium plays an important role in organic chemistry also. It is a part of organometallic compounds known as Grignard reagents. The Grignard reagent is important in organic chemistry as this reagent is used to synthesize different alcohols.

Manufacture of Magnesium:

The following are the methods that are used in industry for the production of this metal.

  1. Dolomite and magnesite are two important minerals from which the metal will be extracted. The ore is well crushed, roasted and then seawater will be added. The formed magnesium hydroxide will be filtered and made to react with hydrochloric acid. Magnesium chloride will be formed and electrolysis is carried out to get magnesium metal.

  2. This process is known as Pidgeon Process. This is another process very widely used. In this process, closed-end retorts made of nickel-chromium-steel alloy are used. These are filled with calcined dolomite ore and ferrosilicon. Then these retorts are heated till magnesium is obtained. The process uses more energy and labour.

  3. Magensium will also be produced from seawater.

Magnesium uses:

Some important uses of this metal are mentioned below

  1. Magnesium is very important for the human body for the proper growth and maintenance of bones, for the proper function of nerves, muscles and many other parts of the body. Magnesium helps to neutralize the acid in our body and moves stools through the intestine.

  2. Magnesium is very commonly used for constipation, as an antacid, for low magnesium levels, for pregnancy complications and for a certain type of irregular heartbeat.

  3. The density of magnesium is almost two-thirds that of aluminium. But it is more costly than aluminium. So an alloy of these two metals, namely magnesium and aluminium, is used widely in industry. This alloy will have better mechanical, fabrication and welding characteristics than aluminium. These alloys are useful in aeroplane and car construction. As the material is light in weight this is used in making car seats, laptops, cameras and power tools etc.

  4. This magnesium metal ignites easily in the air and burns with a bright light. Hence it is very widely used in flares, fireworks pyrotechnics and sparklers.

  5. Magnesium sulfate is used as a mordant for dyes.

  6. Magnesium hydroxide is used in plastics

  7. Magnesium oxide is used to make heat-resistant bricks for fireplaces and furnaces.


Magnesium is having uses in various filed including the health care industry, aerospace industry and the pyrotechnic industry. Magnesium is also the main constituent in our bones and the strength of the bones will depend on this constituent. Magnesium plays a significant role in the digestive system of our body also.


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