Roentgenium is an extremely radioactive synthetic element named after physicist Wilhelm Röntgen.
Core Principles & Analysis
Roentgenium was synthesized in December 1994 at GSI, weeks after darmstadtium, by bombarding bismuth-209 with nickel-64; only three atoms were observed in the first experiment.
In 2004 it was named for Wilhelm Conrad Roentgen, whose 1895 discovery of X-rays opened the experimental study of atomic structure.
Its longest-lived known isotope, roentgenium-282, has a half-life of roughly 100 seconds, and theory predicts roentgenium is an extremely noble metal, a relativistic analog of gold.
Specifications & Metrics
NUM: 111
SYMBOL: Rg
CATEGORY: Unknown Properties
ATOMIC MASS: 282.169 u
ELECTRON CONFIGURATION: [Rn]7s2 5f14 6d9 (predicted)