Roentgenium
From Chemistry Resource
| Roentgenium | |
|---|---|
| Symbol | Rg |
| Atomic number | 111 |
| Atomic mass | (272) amu |
Roentgenium was officially discovered at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany on December 8, 1994. In 2001, the IUPAC/IUPAP Joint Working Party (JWP) concluded that there was insufficient evidence for the discovery. In 2004, element 111's official name of roentgenium (Rg) was accepted.