Attribute | Francium × | Astatine × |
---|---|---|
Standard state | Solid | Solid |
Electron configuration | [Rn]7s¹ | [Xe]6s²4f¹⁴5d¹⁰6p⁵ |
Atomic mass (u) | 223.01973 | 209.98715 |
Electronegativity (pauling scale) | 0.7 | 2.2 |
1↓Oxidation states |
|
|
Ionization energy (eV) | 3.9 | 9.5 |
Atomic radius (van der waals) (pm) | 348 | 202 |
Melting point (K) | 300 | 575 |
Electron affinity (eV) | 0.47 | 2.8 |
Density (g/cm³) | - | 7 |
Atomic number | 87 | 85 |
Group name | Alkali metal | Halogen |
Symbol | Fr | At |
Discovered (year) | 1939 | 1940 |