Manganese Manganese Manganese is a chemical element with symbol Mn and atomic number 25. It is not found as a free element in nature; it is often found in minerals in combination with iron. Manganese is a metal with important industrial metal alloy uses, particularly in stainless steels. Historically, manganese is named for pyrolusite and other black minerals from the region of Magnesia in Greece, which also gave its name to magnesium and the iron ore magnetite. By the mid-18th century, Swedish-German chemist Carl Wilhelm Scheele had used pyrolusite to produce chlorine. Scheele and others were aware that pyrolusite (now known
Manganese heptoxide Manganese heptoxide Manganese(VII) oxide (manganese heptoxide) is an inorganic compound with the formula MnO. This volatile liquid is highly reactive and more often discussed than intentionally prepared. It is a dangerous oxidizer and was first described in 1860. It is the acid anhydride of permanganic acid. The crystalline form of this chemical compound is dark green. The liquid is green by reflected light and red by transmitted light. It is soluble in carbon tetrachloride, and decomposes when in contact with water. It melts at only 5.9 °C, and sublimes at −10 °C. These properties indicate a nonpolar molecular species, which