Discovery date : 1994
Discovered by: Peter Armbruster and Gottfried Münzenberg
Origin of the name: The name roentgenium (Rg) was proposed by the GSI team in honour of the German physicist Wilhelm Conrad Röntgen,
and was accepted as a permanent name on November 1, 2004
Allotropes :
~>ROENTGENIUM is a synthetic chemical element with symbol Rg and atomic number 111. It is a synthetic element that can be created in a laboratory but is not found in nature.
| FACT BOX | |||
| Group | 11 | Melting point | Unknown |
| Period | 7 | Boiling point | Unknown |
| Block | d | Density (g cm−3) | Unknown |
| Atomic number | 111 | Relative atomic mass | [280] |
| State at 20°C | Solid | Key isotopes | 280Rg |
| Electron configuration | [Rn] 5f146d107s1 | CAS number | 54386-24-2 |
| ChemSpider ID | - | ChemSpider is a free chemical structure database | |
There are seven known isotopes of the element: 272, 274 and 278-282. The longest lived is isotope 281 which has a half-life of 22.8 seconds. In 1986, physicists at the Russian Joint Institute for Nuclear Research (JINR), bombarded bismuth with nickel hoping to make element 111, but they failed to detect any atoms of element 111. In 1994, a team led by Peter Armbruster and Gottfred Munzenberg at the German Geselleschaft für Schwerionenforschung (GSI), were successful when they bombarded bismuth with nickel and they obtained few atoms of isotope 272. It had a half-life of 1.5 milliseconds.