Element: Bohrium
This element has only been produced a few atoms at a time, so most of its properties have never been measured - missing values are omitted.
General data
| Element name | Bohrium |
|---|---|
| Chemical symbol | Bh |
| Atomic number Z | 107 |
| Year discovered | 1976 |
| Standard state (25°C) | Solid |
| Category | Transition metal |
| Block | d |
| Atomic mass | [278] |
| CPK color | #E00038 |
Physical properties
none - only single atoms have been produced
Energy properties
none - only single atoms have been produced
Atomic structure
| Protons | 107 (Atomic number) |
|---|---|
| Neutrons (Bh-278, longest-lived isotope) | 171 |
| Electrons | 107 |
| Electron configuration | [Rn] 7s² 5f¹⁴ 6d⁵ |
| Oxidation states | +7, +5, +4, +3 |
Ionization energies - NIST ASD (72 states)
| State | Charge | Ioniz. energy (eV) | Type |
|---|---|---|---|
| Bh I | 0+ | 7.7 ± 0.5 | semi-empirical |
| Bh II | 1+ | 17.5 ± 0.5 | semi-empirical |
| Bh III | 2+ | 26.7 ± 0.5 | semi-empirical |
| Bh IV | 3+ | 37.3 ± 0.5 | semi-empirical |
| Bh V | 4+ | 49 ± 0.5 | semi-empirical |
| Bh VI | 5+ | 62.1 ± 0.5 | semi-empirical |
| Bh VII | 6+ | 74.9 ± 0.5 | semi-empirical |
| Bh VIII | 7+ | 134 ± 2.1 | calculated |
| Bh IX | 8+ | 148 ± 2.2 | calculated |
| Bh X | 9+ | 178 ± 2.2 | calculated |
| Bh XI | 10+ | 198 ± 2.4 | calculated |
| Bh XII | 11+ | 228 ± 2.5 | calculated |
| Bh XIII | 12+ | 255 ± 3 | calculated |
| Bh XIV | 13+ | 281 ± 3 | calculated |
| Bh XV | 14+ | 318 ± 3 | calculated |
| Bh XVI | 15+ | 337 ± 3 | calculated |
| Bh XVII | 16+ | 374 ± 3 | calculated |
| Bh XXX | 29+ | 934 ± 4 | calculated |
| Bh XXXI | 30+ | 969 ± 4 | calculated |
| Bh XXXII | 31+ | 1008 ± 4 | calculated |
| Bh XXXIII | 32+ | 1049 ± 4 | calculated |
| Bh XXXIV | 33+ | 1088 ± 5 | calculated |
| Bh XXXV | 34+ | 1126 ± 5 | calculated |
| Bh XXXVI | 35+ | 1197 ± 5 | calculated |
| Bh XXXVII | 36+ | 1237 ± 5 | calculated |
| Bh XXXVIII | 37+ | 1280 ± 4 | calculated |
| Bh XXXIX | 38+ | 1320 ± 4 | calculated |
| Bh LXII | 61+ | 4216 ± 12 | calculated |
| Bh LXIII | 62+ | 4301 ± 15 | calculated |
| Bh LXIV | 63+ | 4390 ± 19 | calculated |
| Bh LXV | 64+ | 4486 ± 24 | calculated |
| Bh LXVI | 65+ | 4580 ± 30 | calculated |
| Bh LXVII | 66+ | 4660 ± 40 | calculated |
| Bh LXVIII | 67+ | 4890 ± 40 | calculated |
| Bh LXIX | 68+ | 4980 ± 50 | calculated |
| Bh LXX | 69+ | 5080 ± 50 | calculated |
| Bh LXXI | 70+ | 5170 ± 60 | calculated |
| Bh LXXII | 71+ | 5550 ± 60 | calculated |
| Bh LXXIII | 72+ | 5640 ± 70 | calculated |
| Bh LXXIV | 73+ | 5740 ± 90 | calculated |
| Bh LXXV | 74+ | 5830 ± 90 | calculated |
| Bh LXXVI | 75+ | 6650 ± 100 | calculated |
| Bh LXXVII | 76+ | 6760 ± 110 | calculated |
| Bh LXXVIII | 77+ | 7040 ± 120 | calculated |
| Bh LXXIX | 78+ | 7140 ± 120 | calculated |
| Bh LXXX | 79+ | 10930 ± 140 | calculated |
| Bh LXXXI | 80+ | 11130 ± 150 | calculated |
| Bh LXXXII | 81+ | 11340 ± 160 | calculated |
| Bh LXXXIII | 82+ | 11560 ± 170 | calculated |
| Bh LXXXIV | 83+ | 11780 ± 190 | calculated |
| Bh LXXXV | 84+ | 11980 ± 200 | calculated |
| Bh LXXXVI | 85+ | 12610 ± 220 | calculated |
| Bh LXXXVII | 86+ | 12830 ± 240 | calculated |
| Bh LXXXVIII | 87+ | 13070 ± 250 | calculated |
| Bh LXXXIX | 88+ | 13300 ± 300 | calculated |
| Bh XC | 89+ | 13900 ± 300 | calculated |
| Bh XCI | 90+ | 14100 ± 300 | calculated |
| Bh XCII | 91+ | 14300 ± 300 | calculated |
| Bh XCIII | 92+ | 14500 ± 400 | calculated |
| Bh XCIV | 93+ | 17000 ± 400 | calculated |
| Bh XCV | 94+ | 17300 ± 400 | calculated |
| Bh XCVI | 95+ | 17700 ± 400 | calculated |
| Bh XCVII | 96+ | 18000 ± 400 | calculated |
| Bh XCVIII | 97+ | 35200 ± 400 | calculated |
| Bh XCIX | 98+ | 35700 ± 500 | calculated |
| Bh C | 99+ | 36300 ± 500 | calculated |
| Bh CI | 100+ | 36800 ± 500 | calculated |
| Bh CII | 101+ | 46100 ± 500 | calculated |
| Bh CIII | 102+ | 46900 ± 500 | calculated |
| Bh CIV | 103+ | 47800 ± 500 | calculated |
| Bh CVI | 105+ | 187260 ± 12 | calculated |
| Bh CVII | 106+ | 190329 ± 12 | calculated |
Value type as given by NIST ASD: measured - from evaluated experimental data; calculated - from ab initio calculations (mostly highly ionised atoms that have not been measured; for the simplest ones, e.g. H I, the calculation is more accurate than measurement); semi-empirical - from interpolation, extrapolation or another semi-empirical method.
NIST gives no energy for some ionization stages - hence the gaps in numbering.
Data sources
- PubChem Periodic Table API - Retrieved on 29 June 2026 - licence: CC0
- IUPAC CIAAW - Abridged Standard Atomic Weights 2024 - Table version: 2024 - licence: Public domain
- NNDC Wallet Cards 2023 - Data as of 15 October 2024 - licence: Public domain
- NIST Atomic Spectra Database (ASD) - Retrieved on 29 June 2026 - licence: © U.S. Secretary of Commerce