roentgenium

Roentgenium is a synthetic chemical element with atomic number 111 and the symbol Rg. All isotopes of the element are highly radioactive, with half-lives measured in seconds or minutes. Only a handful of roentgenium atoms have ever been created. It has no applications outside of pure research.

It was first produced in 1994 by a team led by Sigurd Hofmann at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany. Subsequent experiments in 2002 confirmed the existence of roentgenium, and the International Union of Pure and Applied Chemistry invited Hoffmann and his team to submit a proposed name in 2033:

The 2003 JWP report concluded that the criteria for discovery of an element had been fulfilled only in the case of element 111 and this by the collaboration of Hofmann et al. Following this assignment and in accordance with the procedures established by IUPAC for the naming of elements, the discoverers at GSI were invited to propose a name and symbol for element 111. The discoverers propose the name roentgenium and the symbol Rg.

This proposal lies within the long-established tradition of naming elements to honor famous scientists. Wilhelm Conrad Roentgen discovered X-rays in 1895. Their use has subsequently revolutionized medicine, found wide application in technology, and heralded the age of modern physics based on atomic and nuclear properties.

The physicist’s name is spelled Röntgen in German, but the element is spelled with an <e> replacing the umlaut as IUPAC does not use diacritical marks in its nomenclature.

Discuss this post

Sources:

Corish, J. and G. M. Rosenblatt. “Name and Symbol of the Element with Atomic Number 111 (IUPAC Recommendations 2004).” Pure and Applied Chemistry, 76.12 (2004), 2101–03 at 2102. DOI: 10.1351/pac200476122101.

Miśkowiec, Pawel. “Name Game: The Naming History of the Chemical Elements—Part 3—Rivalry of Scientists in the Twentieth and Twenty-First Centuries.” Foundations of Chemistry, 12 November 2022. DOI: 10.1007/s10698-022-09452-9.

Oxford English Dictionary, third edition, September 2010, s.v. roentgenium, n.

Image credit: Wilhelm Röntgen, 1895. Wikimedia Commons. Wellcome Collection. Public domain image.