Attribute | Protactinium × | Einsteinium × |
---|---|---|
Atomic mass (u) | 231.03588 | 252.083 |
Standard state | Solid | Solid |
Oxidation states |
|
|
Electron configuration | [Rn]7s²5f²6d¹ | [Rn]7s²5f¹¹ |
Atomic radius (van der waals) (pm) | 243 | 245 |
Electronegativity (pauling scale) | 1.5 | 1.3 |
Melting point (K) | 1845 | 1133 |
Ionization energy (eV) | 5.89 | 6.42 |
Density (g/cm³) | 15.37 | - |
Atomic number | 91 | 99 |
Group name | Actinide | Actinide |
Symbol | Pa | Es |
1↑Discovered (year) | 1913 | 1952 |