Chemical element · Atomic number 9
Fluorine
Fluorine in the periodic table: atomic number 9, electron configuration, atomic mass, physical data, oxidation states, media credit and visible sources.
Halogen
gaseous
18.99840316 u
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Atomic classification
Shell occupancy
Fluorine in the Bohr shell model
This shows the electron distribution of the neutral atom in a simplified shell model.
- K · n=1
- 2 electrons
- L · n=2
- 7 electrons
- Electron configuration
- [He]2s2 2p5
- Electrons per shell
- 2 · 7
- Group
- 17
- Period
- 2
- Block
- P
- Element category
- Halogen
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Physical and chemical properties
- Atomic mass
- 18.99840316 u
- Standard state
- gaseous
- Density
- 0.001696 g/cm³
- Melting point
- 53.53 K
- Boiling point
- 85.03 K
- Electronegativity
- 3.98 (Pauling)
- First ionisation energy
- 17.423 eV
- Oxidation states
- -1
- Discovery
- 1670
Safety and periodic classification
Safety
Safe handling cannot be inferred from Fluorine's position in the periodic table alone. Laboratory, classroom and disposal decisions must follow the documentation for the exact material and its safety data sheet.
Position and comparison
Fluorine is in period 2, group 17 and the P block. Its direct neighbours by atomic number are Oxygen and Neon. The recorded Pauling electronegativity is 3.98. Periodic trends are compared only through the separately sourced neighbouring values.
Sources and scope
PubChem attributes element data to sources including IUPAC, NIST and IAEA. Quanta stores the referenced snapshot locally and leaves unknown values unavailable.