Roentgenium - Rg
Chemical properties of roentgenium
| Atomic number | 111 |
|---|---|
| Representative mass number | 282 (Rg-282; radioactive) |
| Periodic-table group | Group 11 |
| Electron configuration | [Rn] 5f14 6d10 7s1 |
| Density | Unknown |
| Melting point | Unknown |
| Boiling point | Unknown |
| Representative isotope half-life | about 130 seconds for Rg-282, with substantial uncertainty |
Roentgenium (Rg) is a synthetic, radioactive element with atomic number 111. The bracketed representative mass number is the mass number of a radioactive isotope, not a standard atomic weight. Its isotopes decay rapidly, and available measurements are limited to very small numbers of atoms; bulk physical properties such as density, melting point, and boiling point are unknown.
Research and occurrence
Roentgenium is a synthetic, radioactive element named after physicist Wilhelm Conrad Röntgen. Only a small number of atoms have been made, so appearance, density, melting point, and other bulk properties are unknown. It is of research interest only and is not encountered in environmental or process-water treatment.
Health and environmental context
Roentgenium does not occur naturally in measurable quantities and is not an environmental contaminant encountered in ordinary water or process-water treatment. It is handled only in specialised, controlled research settings.
Back to the periodic table of elements.
Sources and further reading
Roentgenium page last reviewed: by Lenntech.