Erbium Selenide

See more Erbium products. Erbium (atomic symbol: Er, atomic number: 68) is a Block F, Group 3, Period 6 element with an atomic radius of 167.259. The number of electrons in each of Erbium's shells is [2, 8, 18, 30, 8, 2] and its electron configuration is [Xe]4f¹² 6s². The erbium atom has a radius of 176 pm and a Van der Waals radius of 235 pm. Erbium was discovered by Carl Mosander in 1843. Sources of Erbium include the mineral monazite and sand ores. Erbium is a member of the lanthanide or rare earth series of elements. In its elemental form, erbium is soft and malleable. It is fairly stable in air and does not oxidize as rapidly as some of the other rare earth metals. Erbium's ions fluoresce in a bright pink color, making them highly useful for imaging and optical applications. It is named after the Swedish town Ytterby where it was first discovered.

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.