9 F Fluorine 18.998
Halogen
Fluorine 氟
[He] 2s² 2p⁵
- Period 2
- Group 17
- Block p
- Gas
Electron configuration
1s² 2s² 2p⁵
Orbital diagram (valence)
2s ↑↓
2p ↑↓↑↓↑
- Electrons per shell
- 2, 7
- Unpaired electrons
- 1
- Zeff (Slater)
- 5.20
Properties
- Atomic weight
- 18.998
- Electronegativity (Pauling)
- 3.98
- First ionization energy
- 1681 kJ/mol
- Electron affinity
- 322.2 kJ/mol
- Covalent radius
- 57 pm
- van der Waals radius
- 135 pm
- Melting point
- 53.53 K
- Boiling point
- 85.03 K
- Density
- 0.001696 g/cm³
- Melting / boiling point
- −219.6 °C / −188.1 °C
- Common oxidation states
- −1
- Discovered
- 1670
Natural isotopes
| Mass number A | Abundance |
|---|---|
| 19F | 100.00 % |
Isotope masses: AME2020; abundances: IUPAC/CIAAW representative values.
Successive ionization energies
The big jumps appear where core electrons start to be removed. Ionization energies from the NIST Atomic Spectra Database.
Fluorine in the course
The lessons that discuss this element most (ranked by mentions).
- Ionic crystals: polyhedra and radius ratios Crystals and solids
- Halogens and noble gases The main-group elements
- The common-ion effect and pH Precipitation and complex ions
- The glass pH electrode and ion-selective electrodes Electroanalytical chemistry
- Bond polarity and electronegativity Chemical bonds
- The solubility product Precipitation and complex ions
- What makes an acid strong Acids and bases
- Symmetry, distortion and the Jahn–Teller effect Coordination chemistry
Periodic trend
Group 17
Data: PubChem periodic table (public domain); atomic weights are IUPAC abridged standard values; covalent radii from Cordero et al. (2008).