The Element Manganese
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Atomic Number: 25
Atomic Weight: 54.938045
Melting Point: 1519 K (1246°C or 2275°F)
Boiling Point: 2334 K (2061°C or 3742°F)
Density: 7.3 grams per cubic centimeter
Phase at Room Temperature: Solid
Element Classification: Metal
Period Number: 4 Group Number: 7 Group Name: none
What's in a name? From the Latin word for magnet, magnes.
Say what? Manganese is pronounced as MAN-ge-nees.
History and Uses:
Proposed to be an element by Carl Wilhelm Scheele in 1774, manganese was discovered by Johan Gottlieb Gahn, a Swedish chemist, by heating the mineral pyrolusite (MnO2) in the presence of charcoal later that year. Today, most manganese is still obtained from pyrolusite, although it is usually burned in a furnace with powdered aluminum or is treated with sulfuric acid (H2SO4) to form manganese sulfate (MnSO4), which is then electrolyzed.
Nearly 90% of all of the manganese produced each year is used in the production of steel. Manganese is added to molten steel to remove oxygen and sulfur and is alloyed with steel to make it easier to form and work with and to increase steel's strength and resistance to impact. Railroad tracks, for example, are made with steel that contains as much as 1.2% manganese. Manganese is also used to give glass an amethyst color and is responsible for the color of amethyst gemstones.
Manganese dioxide (MnO2), the most common compound of manganese, makes up about 0.14% of the Earth's crust. It is used in dry cell batteries to prevent the formation of hydrogen, to remove the green color in glass that is caused by the presence of iron contaminants, and as a drying agent in black paints.
Estimated Crustal Abundance: 9.50×102 milligrams per kilogram
Estimated Oceanic Abundance: 2×10-4 milligrams per liter
Number of Stable Isotopes: 1 (View all isotope data)
Ionization Energy: 7.434 eV
Oxidation States: +7, +4, +3, +2