| Attribute | Fluorine × | Neon × |
|---|---|---|
| Atomic mass (u) | 18.99840316 | 20.18 |
| Standard state | Gas | Gas |
| Oxidation states |
|
|
| Electron configuration | [He]2s²2p⁵ | [He]2s²2p⁶ |
| Atomic radius (van der waals) (pm) | 135 | 154 |
| Electronegativity (pauling scale) | 3.98 | - |
| Electron affinity (eV) | 3.339 | - |
| Ionization energy (eV) | 17.423 | 21.565 |
| Boiling point (K) | 85.03 | 27.07 |
| Melting point (K) | 53.53 | 24.56 |
| Density (g/cm³) | 0.001696 | 0.0008999 |
| Atomic number | 9 | 10 |
| Group name | Halogen | Noble gas |
| Symbol | F | Ne |
| Discovered (year) | 1670 | 1898 |