Manganese

Symbol: Mn
Group #: 7
Group Name: Transition Metal
Atomic #: 25
Mass #: 55
Atomic Mass: 54.938
 
Electron Configuration: 1s22s22p63s23p64s23d5
Physical Properties:
Bpt:  2,097°C
Mpt:  1,244°C
Density: 7.2 grams/mL (at 19.98° C)
Radioactivity: least active in its group
Color:  gray-white
Odor:  none
Hardness: high
Brittle:  high
Malleability: low
 
Chemical Properties: (Click here for Demonstrations!! )
Manganese has very similar chemical property characteristics as iron. It rusts in moist air and burns in air or oxygen at a high temperature. This element will dissolve in dilute mineral acids and other types of acids.
 
History:
In the late 1700ís Carl Wilhelm Scheele, a Swedish chemist, discovered manganese. Johan Gahn, also a Swedish Chemist, was the first to isolate this element as a pure metal. This element is found in open pit mines.  It is a naturally occurring element found mostly in Ukraine, Georgia, and South Africa. This metal is not found in a pure state but rather in the form of ores. To attain pure manganese, manganese dioxide is ignited with aluminum powder. The main ore of manganese is pyrolusite. Other ores include rhodochrosite, psilomelane, franklinite, and manganite. Manganese ranks 12th in its abundance in the earthís crust.
 
Uses:
Manganese is basically used in making alloys of aluminum, copper and magnesium. It is also used in making stainless steel. Ferromanganese is the most important alloy of manganese, which is used in steelmaking. Dry cell batteries and dyes are made with manganese dioxide. Manganese dioxide is also used for coloring glass, ceramics, preparing chlorine and iodine. Manganese sulfate is an important component of some fertilizers; it is used in dying cotton, and is also used in paints. Safes are made of manganese steel, which is approximately 12 percent manganese.
Manganese is essential to plant growth, which is why it is used in some fertilizers. Manganese reduces nitrates in green plants and algae. However, an excess amount of manganese in plants and animals is toxic.
 
References:
Mangan, J. (1987). Manganese. In Comptonís Encyclopedia, (Vol. 14, p. 86). Chicago: Encyclopedia Britannica.

Manganese. (1988). In Britannica Encyclopedia, (Vol. 7, p. 772). Chicago: Encyclopedia Britannica.

Runge, R. (2000, January). Manganese, 1 (1p.) Retrieved March 23, 2000 from the World Wide Web: http://gilligan.esu7.k12.ne.us/`lweb/Lakeview/science/mn.htm

Manganese, 1-2 (2pp.). Retrieved March 23, 2000 from the World Wide Web: http://encarta.msn.com


Kumesha B.
June 6, 2000