Lutetium Selenide

See more Lutetium products. Lutetium (atomic symbol: Lu, atomic number: 71) is a Block F, Group 3, Period 6 element with an atomic weight of 174.9668. The number of electrons in each of Lutetium's shells is [2, 8, 18, 32, 9, 2] and its electron configuration is [Xe] 4f¹⁵ 5d¹ 6s². In its elemental form, lutetium has a silvery-white appearance. The lutetium atom has a radius of 174 pm and a Van der Waals radius of 221 pm. Lutetium was discovered and first isolated by Georges Urbain, Carl Auer von Welsbach and Charles James in 1906, all independently of each other. Urbain was awarded the naming honor because he published his findings first. Lutetium is the last member of the rare earth series. Unlike most rare earths it lacks a magnetic moment. It has the smallest metallic radius of any rare earth and it is perhaps the least naturally abundant of the lanthanides. The most common source of commercially produced lutetium is the mineral monazite. The name lutetium originates from the Latin word Lutetia, meaning Paris. Lutetium is found with almost all other rare earth metals, but it never occurs naturally by itself.

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.