Tris(isopropylcyclopentadienyl)lutetium(III)

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.