Attribute | Argon × | Francium × |
---|---|---|
Electron affinity (eV) | - | 0.47 |
Electronegativity (pauling scale) | - | 0.7 |
Atomic mass (u) | 39.9 | 223.01973 |
Standard state | Gas | Solid |
Oxidation states |
|
|
Electron configuration | [Ne]3s²3p⁶ | [Rn]7s¹ |
Ionization energy (eV) | 15.76 | 3.9 |
Atomic radius (van der waals) (pm) | 188 | 348 |
Boiling point (K) | 87.3 | - |
1↑Melting point (K) | 83.8 | 300 |
Density (g/cm³) | 0.0017837 | - |
Atomic number | 18 | 87 |
Group name | Noble gas | Alkali metal |
Discovered (year) | 1894 | 1939 |
Symbol | Ar | Fr |