To share this content with an AI assistant
Iron
Block dPeriod 4Group 8solid at 20 °C
Configuration :[Ar] 3d⁶ 4s²
Atomic mass :55.845 u
French :Fer
Latin :Ferrum
3D Bohr-model representation of the Iron atom (symbol Fe, atomic number Z=26). Electron shell configuration: 2, 8, 14, 2 electrons.
Scroll to activate 3D
Bohr model · educational
Electron 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.