Roentgenium is a chemical element with symbol Rg and atomic number 111. It is an extremely radioactive synthetic element (an element that can be created in a laboratory but is not found in nature); the most stable known isotope, roentgenium-282, has a half-life of 2.1 minutes. Roentgenium was first created in 1994 by the GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany.
Three reasons Roentgenium stands out
- 1
Named after German physicist who discovered X-rays.
- 2
It was first synthesised in 1994 by bombarding bismuth with nickel nuclei in a heavy-ion accelerator.
- 3
It breaks down quickly after being created.
X-rays remembered in a superheavy nucleus
Roentgenium honors Wilhelm Röntgen, discoverer of X-rays. It sits beneath gold in group 11, but no macroscopic sample exists to display a golden color or metallic surface. Calculations suggest relativistic electron behavior may give it properties unlike a straightforward heavier gold atom.