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