Element 111
Roentgenium (Rg)
Roentgenium (Rg) is element 111 of the periodic table, a element with unclassified properties in period 7, group 11 (d-block) with an atomic mass of 282 and is a solid at standard conditions.
At a glance
- Atomic number
- 111
- Symbol
- Rg
- Atomic mass
- 282 u
- Category
- Unclassified properties
- Period
- 7
- Group
- 11
- Block
- d-block
- Phase at STP
- solid
Electron structure
- Electron configuration
- 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6 5f14 6d9 7s2
- Shorthand configuration
- [Rn] 5f14 6d9 7s2
- Electrons per shell
- 2, 8, 18, 32, 32, 17, 2
- Oxidation states
- +5
Physical properties
- Density
- 28.7 g/cm3
- Phase
- solid
Atomic properties
- Covalent radius
- 121 pm
- First ionization energy
- 1020 kJ/mol
- Electron affinity
- 151 kJ/mol
Notable isotopes
| Isotope | Mass | Abundance | Stability |
|---|---|---|---|
| Rg-282 | 282.16912 | — | Half-life 100 seconds |
Common uses
- Scientific research only
Discovery
- Year
- 1994
- Discovered by
- Sigurd Hofmann
- Country
- Germany