3D Bohr-model representation of the Iron atom (symbol Fe, atomic number Z=26). Electron shell configuration: 2, 8, 14, 2 electrons.
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Bohr model · educational
Bohr model of iron
Iron (Fe) has 26 electrons, spread over 4 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) | 8 |
| M (n = 3) | 14 |
| N (n = 4) | 2 |
The Bohr model is a teaching picture: electrons do not travel in circular orbits, but the number of electrons per shell is exact.
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Three quantities linked by a simple formula. How to measure each, and why density is a characteristic property.
8 minElectron configuration
Full1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶ 4s²
Short[Ar] 3d⁶ 4s²
Valence electrons8
KLMNOPQ shells
K2
L8
M14
N2
Electronegativity
Pauling1.83
Allen1.8
Mulliken (eV)—
Atomic radii
Empirical140 pm
Calculated156 pm
Covalent132 pm
Van der Waals—
Ionic radii (Shannon-Prewitt)
+278 pm
+364.5 pm
Successive ionisation energies
I₁762.5 kJ/mol
I₂1561.9 kJ/mol
I₃2957 kJ/mol
I₄5290 kJ/mol
I₅7240 kJ/mol
Electron affinity15.7 kJ/mol
Oxidation states
-4-2-10+1+2+3+4+5+6+7
Bold states = most common.
Warm-up
Iron — 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