Attribute | Fermium × | Berkelium × |
---|---|---|
Atomic mass (u) | 257.09511 | 247.07031 |
Standard state | Solid | Solid |
1↑Oxidation states |
|
|
Electron configuration | [Rn]5f¹²7s² | [Rn]7s²5f⁹ |
Atomic radius (van der waals) (pm) | - | 244 |
Electronegativity (pauling scale) | 1.3 | 1.3 |
Melting point (K) | 1800 | 1323 |
Ionization energy (eV) | 6.5 | 6.23 |
Density (g/cm³) | - | 14 |
Atomic number | 100 | 97 |
Group name | Actinide | Actinide |
Symbol | Fm | Bk |
Discovered (year) | 1952 | 1949 |