Properties | More Info | Isotopes | Spectra
Compounds | Reactions | Production
Atomic: M.A.C. | Reference
Diagrams: Shell | Atomic Radius | Electron || Images
Iron
Electrons per shell 2,8,14,2
Electron Configuration [Ar] 3d6 4s2 open electron config
Ground state 5D4
Atomic Volume 7.1 cm3 mol-1
Electronegativity 1.83
Magnetic ordering Ferromagnetic
Speed of sound 5120 m s-1
Thermal Properties
Enthalpy of Atomization 414.2 kJ mol-1 @25°C
Enthalpy of Fusion 14.9 kJ mol-1
Enthalpy of Vaporisation 340.2 kJ mol-1
Heat Capacity 25.10 J mol-1 K-1
Thermal Conductivity 80.4 W m-1 K-1
Thermal Expansion 11.8 μm m-1 K-1
Hardness
Brinell hardness 490 MPa
Mohs hardness 4.0
Vickers hardness 608 MPa
Elastic Properties
Bulk modulus 170 GPa
Poisson ratio 0.29
Shear modulus 82 GPa
Young's modulus 211 GPa
Electrical Properties
Electrical resistivity 9.7 x 10-8 Ω m
Electrical conductivity 0.0993 106/cm Ω
Chemical Properties
Electrochemical Equivalent 0.69455 g Ah-1
Electron Work Function 4.7 eV
Valence Electron Potential (-eV) 67
Ionization Potential  
First 7.87
Second 16.18
Third 30.651
Energy Levels
Kα1 (intensity 100) 6.40384 KeV
Kα2 (intensity 50) 6.39084 KeV
Kβ1 (intensity 20.4) 7.05798 KeV
Lα1 (intensity 100) 0.705 KeV
Lα2 (intensity 10) 0.705 KeV
Lβ1 (intensity 15) 0.7185 KeV
Lβ3 (intensity 0.5) 0.792 KeV
Lβ4 (intensity 0.5) 0.792 KeV
Lγ3 (intensity 15) 0.628 KeV
Ll (intensity 38) 0.6146 KeV
Atomic Radii
Empirical 140 pm
Bohr Radius 156 pm
Covalent Radius 125 pm
Van der Waals No data.
Triple covalent 102 pm
Metallic 126 pm
Oxidation States
Main Fe+2, Fe+3
Other Fe-2, Fe-1, Fe0, Fe+1, Fe+4, Fe+5, Fe+6
Ionisation Energies (kJ mol-1) show graph
M - M+ 759.3
M+ - M2+ 1561
M2+ - M3+ 2957
M3+ - M4+ 5290
M4+ - M5+ 7240
M5+ - M6+ 9600
M6+ - M7+ 12100
M7+ - M8+ 14575
M8+ - M9+ 22678
M9+ - M10+ 25290
Vapour Pressure
P (Pa) 1 10 100 1K 10K 100K
T (K) 1728 1890 2091 2346 2679 3132
Crystal Structure
Structure Body centred cubic
a = 286.65 pm
b = 286.65 pm
c = 286.65 pm
α = 90°
β = 90°
γ = 90°