9F18.9984
Fluorine
HalogensBlock pPeriod 2Group 17gas at 20 °C
- Configuration :
- [He] 2s² 2p⁵
- Atomic mass :
- 18.998403163 u
- French :
- Fluor
3D Bohr-model representation of the Fluorine atom (symbol F, atomic number Z=9). Electron shell configuration: 2, 7 electrons.
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Bohr model · educational
Bohr model of fluorine
Fluorine (F) has 9 electrons, spread over 2 shells. The diagram places them on circles around the nucleus, from the K shell — the closest — outward.
| Shell | Electrons |
|---|---|
| K (n = 1) | 2 |
| L (n = 2) | 7 |
The Bohr model is a teaching picture: electrons do not travel in circular orbits, but the number of electrons per shell is exact.
Related lesson
First look at the periodic classification
Reading the table, spotting families (alkali metals, halogens, noble gases). Why some elements share properties.
9 minElectron configuration
Full1s² 2s² 2p⁵
Short[He] 2s² 2p⁵
Valence electrons7
KLMNOPQ shells
K2
L7
Electronegativity
Pauling3.98
Allen4.193
Mulliken (eV)—
Atomic radii
Empirical50 pm
Calculated42 pm
Covalent57 pm
Van der Waals147 pm
Ionic radii (Shannon-Prewitt)
-1133 pm
Successive ionisation energies
I₁1681 kJ/mol
I₂3374.2 kJ/mol
I₃6050.4 kJ/mol
I₄8407.7 kJ/mol
I₅11022.7 kJ/mol
Electron affinity328 kJ/mol
Oxidation states
-1
Bold states = most common.
Warm-up
Fluorine — do you remember?
3 questions on this page. The right answer shows every time, and nothing is asked of you to play.
No account · one minute