Manganese is a chemically active element which is pinkish-gray in colour and a member of group 7 elements. Its atomic number is 25 and it is symbolized as Mn. Besides being a very had metal it is also very brittle. It does not melt easily and like iron it rusts when it reacts with water. It is very reactive when pure and dissolves in diluted acids. It is not a magnetic material and it tarnishes when exposed to air and when heated.

The pure sample of Manganese was first isolated in 1774 by John Gahn, a Swedish chemist, by reacting pyrolusite with Carbon. It was recommended to be an element by Carl Wilhelm Scheele and later discovered by John when he heated pyrolusite in the existence of a burning charcoal. The pure metal exists in some forms called the allotropic forms; alpha which is steady at regular temperatures, the gamma which transforms to alpha at regular temperatures. Unlike the hard alpha type, the gamma type is flexible, soft and easily cut.

Manganese is the fifth most plentiful metal found in the earth’s crust, it is found in the soil in the form of oxides and hydroxides. Mainly the element occurs as pyrolusite and to some degree rhodochrosite. Every year an estimate of about twenty five million tonnes are mined. Manganese reserves are approximated to go over three billion tonnes. Organism like molluscs, diatoms and sponges which live in the water accumulate manganese therefore 24% of manganese nodules have been discovered on the ocean floor. Manganese ores are majorly mined in the following countries, Russia, Georgia, South Africa, Gabon, and Australia.

Manganese is used in forming many important alloys; it is widely used to make a cheap stainless aluminium alloys. It is an important element in iron and steel production because it improves the hardness, strength, hardness, toughness, stiffness and wear resistance of these metals;it boosts the forging and rolling qualities of steel. It is also used with aluminium, copper and antimony in the production of materials with magnetic properties (ferromagnetic materials). Manganese dioxide is used to depolarise dry cells and in decolourizing glass and in making violet coloured glass. Manganese dioxide is also widely used as a catalyst in the preparation of oxygen and chlorine. Potassium permanganate which is a compound of Manganese is used as a disinfectant and in qualitative analysis and in medicine. Manganese oxide is used in making ceramics. It is also used to reduce the discolouration of green gas by iron oxides and also in drying black paint.

Manganese is often present in water both groundwater and surface water and usually with Iron. Manganese finds it ways in the water when rocks rich in manganese are opened to the elements of acidic water in the absence of oxygen. It can also originate as organic complexes. It is an essential element in nutrition but toxic in higher quantities. High levels of Manganese in the human body have been known for causing impaired motor skills and mental disorders.