Element: Dubnium
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 | Dubnium |
|---|---|
| Chemical symbol | Db |
| Atomic number Z | 105 |
| Year discovered | 1967 |
| Standard state (25°C) | Solid |
| Category | Transition metal |
| Block | d |
| Atomic mass | [268] |
| CPK color | #D1004F |
Physical properties
none - only single atoms have been produced
Energy properties
none - only single atoms have been produced
Atomic structure
| Protons | 105 (Atomic number) |
|---|---|
| Neutrons (Db-268, longest-lived isotope) | 163 |
| Electrons | 105 |
| Electron configuration | [Rn] 7s² 5f¹⁴ 6d³ |
| Oxidation states | +5, +4, +3 |
Ionization energies - NIST ASD (70 states)
| State | Charge | Ioniz. energy (eV) | Type |
|---|---|---|---|
| Db I | 0+ | 6.8 ± 0.5 | calculated |
| Db II | 1+ | 14 ± 1.6 | calculated |
| Db III | 2+ | 23.1 ± 1.6 | calculated |
| Db IV | 3+ | 33 ± 1.7 | calculated |
| Db V | 4+ | 43 ± 1.9 | calculated |
| Db VI | 5+ | 86 ± 2 | calculated |
| Db VII | 6+ | 98.9 ± 2 | calculated |
| Db VIII | 7+ | 126 ± 2.1 | calculated |
| Db IX | 8+ | 145.1 ± 2.2 | calculated |
| Db X | 9+ | 172 ± 2.2 | calculated |
| Db XI | 10+ | 196 ± 2.4 | calculated |
| Db XII | 11+ | 220.9 ± 2.5 | calculated |
| Db XIII | 12+ | 254 ± 3 | calculated |
| Db XIV | 13+ | 274 ± 3 | calculated |
| Db XV | 14+ | 307 ± 3 | calculated |
| Db XXVIII | 27+ | 838 ± 4 | calculated |
| Db XXIX | 28+ | 872 ± 4 | calculated |
| Db XXX | 29+ | 908 ± 4 | calculated |
| Db XXXI | 30+ | 948 ± 4 | calculated |
| Db XXXII | 31+ | 985 ± 4 | calculated |
| Db XXXIII | 32+ | 1022 ± 4 | calculated |
| Db XXXIV | 33+ | 1089 ± 5 | calculated |
| Db XXXV | 34+ | 1126 ± 5 | calculated |
| Db XXXVI | 35+ | 1168 ± 5 | calculated |
| Db XXXVII | 36+ | 1207 ± 5 | calculated |
| Db LX | 59+ | 3975 ± 7 | calculated |
| Db LXI | 60+ | 4057 ± 10 | calculated |
| Db LXII | 61+ | 4145 ± 12 | calculated |
| Db LXIII | 62+ | 4237 ± 15 | calculated |
| Db LXIV | 63+ | 4326 ± 19 | calculated |
| Db LXV | 64+ | 4411 ± 24 | calculated |
| Db LXVI | 65+ | 4620 ± 30 | calculated |
| Db LXVII | 66+ | 4710 ± 40 | calculated |
| Db LXVIII | 67+ | 4810 ± 40 | calculated |
| Db LXIX | 68+ | 4900 ± 50 | calculated |
| Db LXX | 69+ | 5260 ± 50 | calculated |
| Db LXXI | 70+ | 5350 ± 60 | calculated |
| Db LXXII | 71+ | 5450 ± 60 | calculated |
| Db LXXIII | 72+ | 5530 ± 70 | calculated |
| Db LXXIV | 73+ | 6280 ± 90 | calculated |
| Db LXXV | 74+ | 6380 ± 90 | calculated |
| Db LXXVI | 75+ | 6650 ± 100 | calculated |
| Db LXXVII | 76+ | 6760 ± 110 | calculated |
| Db LXXVIII | 77+ | 10420 ± 120 | calculated |
| Db LXXIX | 78+ | 10610 ± 120 | calculated |
| Db LXXX | 79+ | 10820 ± 140 | calculated |
| Db LXXXI | 80+ | 11040 ± 150 | calculated |
| Db LXXXII | 81+ | 11240 ± 160 | calculated |
| Db LXXXIII | 82+ | 11440 ± 170 | calculated |
| Db LXXXIV | 83+ | 12040 ± 190 | calculated |
| Db LXXXV | 84+ | 12250 ± 200 | calculated |
| Db LXXXVI | 85+ | 12480 ± 220 | calculated |
| Db LXXXVII | 86+ | 12700 ± 240 | calculated |
| Db LXXXVIII | 87+ | 13300 ± 250 | calculated |
| Db LXXXIX | 88+ | 13500 ± 300 | calculated |
| Db XC | 89+ | 13700 ± 300 | calculated |
| Db XCI | 90+ | 13900 ± 300 | calculated |
| Db XCII | 91+ | 16200 ± 300 | calculated |
| Db XCIII | 92+ | 16400 ± 400 | calculated |
| Db XCIV | 93+ | 16900 ± 400 | calculated |
| Db XCV | 94+ | 17100 ± 400 | calculated |
| Db XCVI | 95+ | 33800 ± 400 | calculated |
| Db XCVII | 96+ | 34300 ± 400 | calculated |
| Db XCVIII | 97+ | 34800 ± 400 | calculated |
| Db XCIX | 98+ | 35300 ± 500 | calculated |
| Db C | 99+ | 43800 ± 500 | calculated |
| Db CI | 100+ | 44500 ± 500 | calculated |
| Db CII | 101+ | 45400 ± 500 | calculated |
| Db CIV | 103+ | 178505 ± 10 | calculated |
| Db CV | 104+ | 181445 ± 10 | 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