Fluorine (F)
Fluorine (F) is element 9, a halogen. Atomic mass 18.998403162, configuration [He] 2s² 2p⁵. Properties, isotopes, oxidation states, uses and history, with an interactive 3D atom model.
Key facts
| Atomic number | 9 |
|---|---|
| Symbol | F |
| Standard atomic weight | 18.998403162(5) |
| Category | Halogen |
| Group | 17 |
| Period | 2 |
| State at room temperature | Gas |
| Electron configuration | [He] 2s² 2p⁵ |
| Valence electrons | 7 |
| Common oxidation states | -1 |
| Common ions | F⁻ |
| Electronegativity (Pauling) | 3.98 |
| First ionization energy | 1681 kJ/mol |
| Electron affinity | 328.2 kJ/mol |
| Atomic radius | 42 pm |
| Density | 1.553 g/L |
| Melting point | -219.61°C |
| Boiling point | -188.12°C |
| Specific heat | 0.824 J/(g·°C) |
Natural isotopes
- F-19: Stable
Common uses
- Teflon (PTFE)
- Toothpaste
- Refrigerants
Where it matters
- Dental health (Water fluoridation)
- Nuclear fuel (UF₆ enrichment)
Hazards
- Highly toxic
- Corrosive
- Reacts with almost everything
History
| Discovered | 1886 |
|---|---|
| Discovered by | Henri Moissan |
| Name | Humphry Davy (suggested) |