111Rg[282]
Roentgenium (Rg)
Element 111 Ā· Transition metal
Roentgenium (Rg) is a chemical element with atomic number 111. It is classified as a transition metal in period 7, group 11 of the periodic table (the d-block). Its most stable known isotope has mass number 282 and its ground-state electron configuration is [Rn] 5fĀ¹ā“ 6dā¹ 7sĀ². Its properties are largely predicted, as only a few atoms have ever been produced.
Roentgenium facts
| Atomic number (Z) | 111 |
|---|---|
| Symbol | Rg |
| Mass number of most stable isotope | [282] |
| Category | Transition metal |
| Group | 11 |
| Period | 7 |
| Block | d-block |
| Electron configuration | [Rn] 5fĀ¹ā“ 6dā¹ 7sĀ² |
| Electronegativity (Pauling) | ā |
| State at 20 Ā°C | Unknown (synthetic) |
| Protons / electrons | 111 / 111 |
| Neutrons (most common isotope, approx.) | 171 |
| Molar mass | 282 g/mol |