Attribute | Meitnerium × | Roentgenium × |
---|---|---|
1↑Discovered (year) | 1982 | 1994 |
Atomic number | 109 | 111 |
Group name | Transition metal | Transition metal |
Oxidation states |
|
|
Electron configuration | [Rn]7s²5f¹⁴6d⁷ (calculated) | [Rn]7s²5f¹⁴6d⁹ (predicted) |
Atomic mass (u) | 277.154 | 282.169 |
Standard state | Solid | Solid (expected) |
Symbol | Mt | Rg |