Fluorine (F) is a halogen with atomic number 9 and atomic mass 18.9984 u. This data sheet describes its fundamental properties, position in the periodic table, and physical characteristics.
Identity
- Name: Fluorine
- Symbol: F
- Atomic number: 9
- Atomic mass: 18.9984 u
Position in the periodic table
- Group: 17 (VIIA)
- Period: 2
- Block: p-block
- Category: Halogen
Physical and chemical properties
- Standard state (25 °C, 1 atm): Gas
- Melting point: −219.67 °C
- Boiling point: −188.11 °C
- Density (at boiling point): 1.696 g/L
- Electron configuration: [He] 2s² 2p⁵
Scientific description
Fluorine is the chemical element with symbol F and atomic number 9. It is the lightest halogen and the most electronegative element (Pauling electronegativity 3.98). At standard conditions it exists as a pale yellow diatomic gas F₂ and is extremely reactive.