Element 9
Fluorine (F)
Fluorine (F) is element 9 of the periodic table, a halogen in period 2, group 17 (p-block) with an atomic mass of 18.998 and is a gas at standard conditions.
At a glance
- Atomic number
- 9
- Symbol
- F
- Atomic mass
- 18.998 u
- Category
- Halogens
- Period
- 2
- Group
- 17
- Block
- p-block
- Phase at STP
- gas
Electron structure
- Electron configuration
- 1s2 2s2 2p5
- Shorthand configuration
- [He] 2s2 2p5
- Electrons per shell
- 2, 7
- Oxidation states
- -1
Physical properties
- Melting point
- 53.53 K
- Boiling point
- 85.03 K
- Density
- 0.001696 g/cm3
- Phase
- gas
Atomic properties
- Electronegativity (Pauling)
- 3.98
- Atomic radius
- 42 pm
- Covalent radius
- 57 pm
- Van der Waals radius
- 147 pm
- First ionization energy
- 1681 kJ/mol
- Electron affinity
- 328 kJ/mol
Notable isotopes
| Isotope | Mass | Abundance | Stability |
|---|---|---|---|
| F-19 | 18.9984 | 100% | Stable |
Common uses
- Toothpaste
- Teflon
- Refrigerants
- Uranium enrichment
Discovery
- Year
- 1886
- Discovered by
- Henri Moissan
- Country
- France