Attribute | Francium × | Krypton × |
---|---|---|
Standard state | Solid | Gas |
Electron affinity (eV) | 0.47 | - |
Electron configuration | [Rn]7s¹ | [Ar]4s²3d¹⁰4p⁶ |
Atomic mass (u) | 223.01973 | 83.8 |
Electronegativity (pauling scale) | 0.7 | 3 |
Oxidation states |
|
|
Ionization energy (eV) | 3.9 | 14 |
Atomic radius (van der waals) (pm) | 348 | 202 |
Boiling point (K) | - | 119.93 |
Melting point (K) | 300 | 115.79 |
Density (g/cm³) | - | 0.003733 |
Atomic number | 87 | 36 |
Group name | Alkali metal | Noble gas |
Symbol | Fr | Kr |
Discovered (year) | 1939 | 1898 |