| Attribute | Meitnerium × | Seaborgium × |
|---|---|---|
| Discovered (year) | 1982 | 1974 |
| Atomic number | 109 | 106 |
| Group name | Transition metal | Transition metal |
| Oxidation states |
|
|
| Electron configuration | [Rn]7s²5f¹⁴6d⁷ (calculated) | [Rn]7s²5f¹⁴6d⁴ |
| Atomic mass (u) | 277.154 | 269.128 |
| Standard state | Solid | Solid |
| Symbol | Mt | Sg |