9 F
Halogen
Fluorine
Most reactive nonmetal.
Properties of Fluorine
- Atomic number (Z)
- 9
- Symbol
- F
- Atomic mass
- 18.998 g/mol
- Category
- Halogen
- Group
- 17
- Period
- 2
- Electron configuration
- [He] 2s² 2p⁵
- Electronegativity (Pauling)
- 3.98
- Atomic radius
- 42 pm
- First ionization energy
- 1681 kJ/mol
- Melting point
- 53.53 K (-219.6 °C)
- Boiling point
- 85.03 K (-188.1 °C)
- Density
- 0.001696 g/cm³
- Phase at 25 °C
- Gas
- Discovered
- Discovered in 1886