109Mt[278]
Meitnerium (Mt)
Element 109 Ā· Transition metal
Meitnerium (Mt) is a chemical element with atomic number 109. It is classified as a transition metal in period 7, group 9 of the periodic table (the d-block). Its most stable known isotope has mass number 278 and its ground-state electron configuration is [Rn] 5fĀ¹ā“ 6dā· 7sĀ². Its properties are largely predicted, as only a few atoms have ever been produced.
Meitnerium facts
| Atomic number (Z) | 109 |
|---|---|
| Symbol | Mt |
| Mass number of most stable isotope | [278] |
| Category | Transition metal |
| Group | 9 |
| Period | 7 |
| Block | d-block |
| Electron configuration | [Rn] 5fĀ¹ā“ 6dā· 7sĀ² |
| Electronegativity (Pauling) | ā |
| State at 20 Ā°C | Unknown (synthetic) |
| Protons / electrons | 109 / 109 |
| Neutrons (most common isotope, approx.) | 169 |
| Molar mass | 278 g/mol |