| Attribute | Meitnerium × | Hassium × |
|---|---|---|
| Discovered (year) | 1982 | 1984 |
| Atomic number | 109 | 108 |
| Group name | Transition metal | Transition metal |
| Oxidation states |
|
|
| Electron configuration | [Rn]7s²5f¹⁴6d⁷ (calculated) | [Rn]7s²5f¹⁴6d⁶ |
| Atomic mass (u) | 277.154 | 269.1336 |
| Standard state | Solid | Solid |
| Symbol | Mt | Hs |