| Attribute | Roentgenium × | Darmstadtium × |
|---|---|---|
| Discovered (year) | 1994 | 1994 |
| Atomic number | 111 | 110 |
| Group name | Transition metal | Transition metal |
| Oxidation states |
|
|
| Electron configuration | [Rn]7s²5f¹⁴6d⁹ (predicted) | [Rn]7s²5f¹⁴6d⁸ (predicted) |
| Atomic mass (u) | 282.169 | 282.166 |
| Standard state | Solid (expected) | Solid (expected) |
| Symbol | Rg | Ds |