Manganese(II) Selenide

See more Manganese products. Manganese (atomic symbol: Mn, atomic number: 25) is a Block D, Group 7, Period 4 element with an atomic weight of 54.938045. The number of electrons in each of Manganese's shells is [2, 8, 13, 2] and its electron configuration is [Ar] 3d⁵ 4s². The manganese atom has a radius of 127 pm and a Van der Waals radius of 197 pm. Manganese was first discovered by Torbern Olof Bergman in 1770 and first isolated by Johann Gottlieb Gahn in 1774. In its elemental form, manganese has a silvery metallic appearance. It is a paramagnetic metal that oxidizes easily in addition to being very hard and brittle. Manganese is found as a free element in nature and also in the minerals pyrolusite, braunite, psilomelane, and rhodochrosite. The name Manganese originates from the Latin word mangnes, meaning "magnet."

See more Selenium products. Selenium (atomic symbol: Se, atomic number: 34) is a Block P, Group 16, Period 4 element with an atomic radius of 78.96. The number of electrons in each of Selenium's shells is 2, 8, 18, 6 and its electron configuration is [Ar] 3d¹⁰ 4s² 4p⁴. The selenium atom has a radius of 120 pm and a Van der Waals radius of 190 pm. Selenium is a non-metal with several allotropes: a black, vitreous form with an irregular crystal structure three red-colored forms with monoclinic crystal structures and a gray form with a hexagonal crystal structure, the most stable and dense form of the element. One of the most common uses for selenium is in glass production the red tint that it lends to glass neutralizes green or yellow tints from impurities in the glass materials. Selenium was discovered and first isolated by Jöns Jakob Berzelius and Johann Gottlieb Gahn in 1817. The origin of the name Selenium comes from the Greek word "Selênê," meaning moon.