6 December 2009
Roentgenium, element 111, was first synthesized in 1994 at the Gesellschaft für Schwerionenforschung (Institute for Heavy Ion Research) in Darmstadt, Germany by a team led by Sigurd Hofmann. The discoverers proposed the name in honor of German physicist Wilhelm Roentgen (1845–1923). Roentgenium was declared the element’s official name by the International Union of Pure and Applied Chemistry (IUPAC) in November 2004.1
The chemical symbol for roentgenium is Rg.
”Name and Symbol of the Element with Atomic Number 111,” Pure and Applied Chemistry, vol. 76, pp. 2101–2103, 2004, http://iupac.org/publications/pac/2004/pdf/7612x2101.pdf.