Georges Urbain

Georges Urbain (12 April 1872 – 5 November 1938) was a French chemist, a professor of the Sorbonne, a member of the Institut de France, and director of the Institute of Chemistry in Paris. Much of his work focused on the rare earths, isolating and separating elements such as europium and gadolinium, and studying their spectra, their magnetic properties and their atomic masses. He discovered the element lutetium (atomic number 71). He also studied the efflorescence of saline hydrates.

Education After attending the Lycée Charlemagne and Lycée Lavoisier, Urbain studied at the École supérieure de physique et de chimie industrielles de la ville de Paris (ESPCI ParisTech). He graduated as the top student in the school's ninth graduating class, in 1894. At that time he also earned his licence ès sciences physique et chimie at the Sorbonne.

Urbain discovered the element lutetium (atomic number 71) independently in 1907 when he demonstrated that Jean Charles Galissard de Marignacs ytterbia contained two substances. Through spectral analysis of both, he was able to characterize them and prove that they were distinct elements. Urbain called his two components "neoytterbia" and "lutecia". and the American chemist Charles James. Urbain and Welsbach accused each other of publishing results based on the other party. The dispute was officially settled in 1909 by the Commission on Atomic Mass, which granted priority to Urbain as the first to describe the separation of lutetium from ytterbium. Urbain's "lutecia" was adapted to "lutetium". Urbain's name "neoytterbium" was temporarily adopted, but later Marignac's name was restored to the element ytterbium.

In 1911 Urbain isolated another new element which he called "celtium", but his studies were interrupted by World War I. In 1922, he announced his new element, fully characterizing its emission spectrum, but mistakenly identifying it as a rare earth. George de Hevesy and Dirk Coster also characterized it, placing it more accurately, and called it "hafnium". A decades-long controversy over credit and naming was eventually decided in favor of hafnium.

As of 1919, Urbain had completed an extensive study of phosphorescence spectra, and demonstrated that trace impurities could dramatically alter results. By introducing impurities into artificially prepared mixtures, he was able to duplicate the results reported by other researchers, again testing claims about possible new elements.

Urbain was also a composer and sculptor.

His son was the hydrologist and climatologist .