Attribute | Berkelium × | Mendelevium × |
---|---|---|
Atomic mass (u) | 247.07031 | 258.09843 |
Standard state | Solid | Solid |
Oxidation states |
|
|
Electron configuration | [Rn]7s²5f⁹ | [Rn]7s²5f¹³ |
Atomic radius (van der waals) (pm) | 244 | - |
Electronegativity (pauling scale) | 1.3 | 1.3 |
1↓Melting point (K) | 1323 | 1100 |
Ionization energy (eV) | 6.23 | 6.58 |
Density (g/cm³) | 14 | - |
Atomic number | 97 | 101 |
Group name | Actinide | Actinide |
Symbol | Bk | Md |
Discovered (year) | 1949 | 1955 |