Bohrium (Bh): electron configuration, atomic mass and facts
Bohrium (Bh) is element 107 of the periodic table, a transition metal (predicted) in period 7, group 7. Its electron configuration is [Rn] 5f14 6d5 7s2, with electrons arranged in shells 2, 8, 18, 32, 32, 13, 2, and its most stable isotope has mass number 270.
▶ Watch Bohrium’s electrons orbit in the interactive periodic tableBohrium at a glance
| Symbol | Bh |
|---|---|
| Atomic number | 107 |
| Atomic mass | [270] u (most stable isotope) |
| Category | Transition metal (predicted) |
| Group | 7 |
| Period | 7 |
| Block | d-block |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d5 7s2 |
| Noble-gas shorthand | [Rn] 5f14 6d5 7s2 |
| Electrons per shell | 2, 8, 18, 32, 32, 13, 2 |
| Electronegativity (Pauling) | — |
| State at 20 °C | Unknown (only a few atoms made) |
Where is Bohrium on the periodic table?
Bohrium is in period 7, group 7, 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, Rhenium 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 Bohrium
Put 107 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), 6d⁵ (107). In shorthand, [Rn] stands for the 86 electrons of radon, giving [Rn] 5f¹⁴ 6d⁵ 7s².
Frequently asked questions
What is the electron configuration of Bohrium?
The electron configuration of Bohrium (Bh) is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d5 7s2. In noble-gas shorthand it is written [Rn] 5f14 6d5 7s2.
How many electrons does Bohrium have in each shell?
Bohrium has 107 electrons arranged in shells as 2, 8, 18, 32, 32, 13, 2.
What is the atomic mass of Bohrium?
Bohrium has no stable isotopes. Its most stable isotope has a mass number of 270.
Is Bohrium a metal?
Yes. Bohrium is a transition metal (predicted).
Explore nearby elements
More transition metals: Rutherfordium, Dubnium, Seaborgium, Hassium, Meitnerium, Darmstadtium. See all elements on the periodic table.