105Db[268]
Dubnium (Db)
Element 105 · Transition metal
Dubnium (Db) is a chemical element with atomic number 105. It is classified as a transition metal in period 7, group 5 of the periodic table (the d-block). Its most stable known isotope has mass number 268 and its ground-state electron configuration is [Rn] 5f¹⁴ 6d³ 7s². Its properties are largely predicted, as only a few atoms have ever been produced.
Dubnium facts
| Atomic number (Z) | 105 |
|---|---|
| Symbol | Db |
| Mass number of most stable isotope | [268] |
| Category | Transition metal |
| Group | 5 |
| Period | 7 |
| Block | d-block |
| Electron configuration | [Rn] 5f¹⁴ 6d³ 7s² |
| Electronegativity (Pauling) | — |
| State at 20 °C | Unknown (synthetic) |
| Protons / electrons | 105 / 105 |
| Neutrons (most common isotope, approx.) | 163 |
| Molar mass | 268 g/mol |