Roentgenium (Rg)
Roentgenium is element 111, a transition metal in period 7, group 11 of the periodic table. At room temperature it is of unknown state (too few atoms have ever been made).
Electron configuration [Rn] 5f14 6d10 7s1
Electrons per shell 2, 8, 18, 32, 32, 18, 1
Roentgenium data
| Atomic number | 111 |
|---|---|
| Symbol | Rg |
| Atomic mass | [280] (mass number of the longest-lived isotope) |
| Category | Transition metal |
| Group | 11 |
| Period | 7 |
| Block | d |
| State at 25 °C | unknown |
| Melting point | — |
| Boiling point | — |
| Density | — |
| Electronegativity (Pauling) | — |
| Atomic radius | — |
| 1st ionization energy | — |
| Electron affinity | — |
| Oxidation states | 0 |
| Common ion charge | — |
| Discovered | 1994 |
Orbital diagram
Each box is one orbital holding up to two electrons of opposite spin. Following Hund’s rule, electrons spread out singly across a subshell before pairing.
Work through roentgenium’s configuration and its ions →
Where roentgenium sits
Roentgenium belongs to the transition metals. To use its mass in a calculation, try the molar mass calculator.
Roentgenium FAQ
What is the electron configuration of roentgenium?
Roentgenium (Z = 111) has the configuration 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p6 5f14 6d10 7s1. In noble-gas shorthand that is [Rn] 5f14 6d10 7s1. This is an exception to the simple Aufbau prediction (1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d9 7s2); a half-filled or filled subshell lowers the energy.
How many valence electrons does roentgenium have?
11 (1 outer s + 10 d electrons; 1 in the outermost shell).
What is the atomic mass of roentgenium?
Roentgenium has no stable isotopes. Its most stable known isotope has mass number 280, so tables list [280].
Is roentgenium a metal?
Yes. Roentgenium is a transition metal.