Roentgenium (Rg): electron configuration, atomic mass and facts
Roentgenium (Rg) is element 111 of the periodic table, a transition metal (predicted) in period 7, group 11. Its electron configuration is [Rn] 5f14 6d9 7s2, with electrons arranged in shells 2, 8, 18, 32, 32, 17, 2, and its most stable isotope has mass number 282.
▶ Watch Roentgenium’s electrons orbit in the interactive periodic tableRoentgenium at a glance
| Symbol | Rg |
|---|---|
| Atomic number | 111 |
| Atomic mass | [282] u (most stable isotope) |
| Category | Transition metal (predicted) |
| Group | 11 |
| Period | 7 |
| Block | d-block |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d9 7s2 |
| Noble-gas shorthand | [Rn] 5f14 6d9 7s2 |
| Electrons per shell | 2, 8, 18, 32, 32, 17, 2 |
| Electronegativity (Pauling) | — |
| State at 20 °C | Unknown (only a few atoms made) |
Where is Roentgenium on the periodic table?
Roentgenium is in period 7, group 11, in the d-block. The period number matches its 7 electron shells, and the block names the subshell its last electrons fill. In the same group, Gold sits directly above it. Elements in the same column of the d-block often have similar chemistry.
How to work out the electron configuration of Roentgenium
Put 111 electrons into subshells in order of rising energy, filling each before starting the next: 1s² (2), 2s² (4), 2p⁶ (10), 3s² (12), 3p⁶ (18), 4s² (20), 3d¹⁰ (30), 4p⁶ (36), 5s² (38), 4d¹⁰ (48), 5p⁶ (54), 6s² (56), 4f¹⁴ (70), 5d¹⁰ (80), 6p⁶ (86), 7s² (88), 5f¹⁴ (102), 6d⁹ (111). In shorthand, [Rn] stands for the 86 electrons of radon, giving [Rn] 5f¹⁴ 6d⁹ 7s².
Frequently asked questions
What is the electron configuration of Roentgenium?
The electron configuration of Roentgenium (Rg) is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d9 7s2. In noble-gas shorthand it is written [Rn] 5f14 6d9 7s2.
How many electrons does Roentgenium have in each shell?
Roentgenium has 111 electrons arranged in shells as 2, 8, 18, 32, 32, 17, 2.
What is the atomic mass of Roentgenium?
Roentgenium has no stable isotopes. Its most stable isotope has a mass number of 282.
Is Roentgenium a metal?
Yes. Roentgenium is a transition metal (predicted).
Explore nearby elements
More transition metals: Seaborgium, Bohrium, Hassium, Meitnerium, Darmstadtium, Copernicium. See all elements on the periodic table.