The element magnesium has atomic number 12 and atomic mass number of 24.3. It is present in the third row and the group IIA of the periodic table. It is a normal element, with a valency of 2 and forms the Mg++ cation. It is a silvery white tough metal with a melting point of 923 K or 1202 F.

Naturally it is found in minerals such as marble, limestone, dolomite, kieserite, magnesia, etc. It is the eighth-most abundant element on the crust of the earth, occupying about 2% of it. Magnesium readily reacts with acids forming respective salts. Most of these salts may are hydrated in their natural states.

Several useful alloys are made using magnesium. Duralumin and magnalium are both lightweight, sturdy alloys that are used to make bodies of aircraft and vehicles. Magnesium has pyrotechnic properties and so it is used in making incendiary bombs, flares and signals. In photography, it is used in the manufacture of flash bulbs. Magnesium also has lubricating and binding properties. Owing to this property, it is used to make industrial capsules. Magnesium finds a use in metallurgy as a reducing agent.

Magnesium is a macro element required for the metabolism of the human body. It is the fourth-most abundant element in the human body and about 50% of it is present in the bones. About 1% of magnesium is assimilated in the human blood. Even chlorophyll in plants is a magnesium-poyphyrin complex. Magnesium is a cofactor for various enzymes. A proper balance of magnesium is required to ward off bone related ailments such as osteoporosis and arthritis. It is also required for proper cardiovascular and kidney functions.

Vegetarian foods have higher contents of magnesium. Magnesium is abundantly found in nuts and green vegetables. It is also abundant in diary products such as tofu, cheese, butter, yoghurt, etc.

Magnesium compounds are sold as therapeutic drugs. Milk of magnesia is the commercial name of magnesium hydroxide. It is used as a laxative and antacid. Magnesium oxide or magnesia is also used for the same. Magnesium sulfate is used to reduce labor pains.