107[270]BhBohrium
Bohrium (Bh) — element 107transition metal · group 7, period 7
Bohrium is a chemical element with the symbol Bh and atomic number 107. It is a transition metal in group 7, period 7 of the periodic table (the d-block), with a standard atomic mass of [270] u. At room temperature (25 °C) bohrium is predicted to be of unknown state.
💡 Known for: Named after Niels Bohr, a pioneer of atomic structure.
# Bohrium properties
| Symbol | Bh |
|---|---|
| Atomic number | 107 |
| Atomic mass | [270] u |
| Category | transition metal |
| Group | 7 |
| Period | 7 |
| Block | d-block |
| Electron configuration | [Rn] 5f¹⁴ 6d⁵ 7s² |
| Full configuration | 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 5f¹⁴ 6s² 6p⁶ 6d⁵ 7s² |
| Electrons per shell | 2, 8, 18, 32, 32, 13, 2 |
| Protons / electrons | 107 / 107 |
| State at 25 °C | unknown |
| Melting point | unknown |
| Boiling point | unknown |
| Density | 37.1 g/cm³ (predicted) |
| Electronegativity (Pauling) | — |
| First ionization energy | — |
| Atomic radius | — |
| Discovered | 1981 |
Values for superheavy elements are theoretical predictions; none have been measured in bulk.
# Electron configuration of bohrium
The electron configuration of bohrium is [Rn] 5f¹⁴ 6d⁵ 7s², written out in full as 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 5f¹⁴ 6s² 6p⁶ 6d⁵ 7s². Its 107 electrons fill 7 shells as 2, 8, 18, 32, 32, 13, 2, so the outermost shell holds 2 electrons. Because only a few atoms have ever been made, this configuration is a theoretical prediction.
# Related elements
SgSeaborgiumprevious elementHsHassiumnext elementMnManganesegroup 7TcTechnetiumgroup 7ReRheniumgroup 7ScScandiumtransition metalTiTitaniumtransition metalVVanadiumtransition metalCrChromiumtransition metalFeIrontransition metalCoCobalttransition metalNiNickeltransition metalCuCoppertransition metal
# Bohrium FAQ
What is the atomic number of bohrium?
The atomic number of bohrium is 107: every bohrium atom has 107 protons in its nucleus. Its symbol is Bh.
What is the atomic mass of bohrium?
The standard atomic mass of bohrium is [270] u (the mass number of its longest-lived isotope, since it has no stable isotopes).
What is the electron configuration of bohrium?
Bohrium's electron configuration is [Rn] 5f¹⁴ 6d⁵ 7s² (1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 5f¹⁴ 6s² 6p⁶ 6d⁵ 7s²), with 2, 8, 18, 32, 32, 13, 2 electrons per shell.
Is bohrium a metal?
Yes. Bohrium is a transition metal, one of the metals.
What is the melting point of bohrium?
The melting point of bohrium is not known. These values are predictions.
What is bohrium used for / known for?
Named after Niels Bohr, a pioneer of atomic structure.