|
|
| Iron | |
| Electron Configuration | 2,8,14,2 |
| Electron Configuration | [Ar] 3d6 4s2 |
| Ground state | 5D4 |
| Atomic Volume | 7.1 g/cm3 |
| 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 | No data. |
| 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 |
| Ionic Radii (Å) |
||||
| Charge | Coordination | Crystal | Ionic | Key |
| 2 | IV (High spin) | 0.77 | 0.63 | |
| IVSQ (High spin) | 0.78 | 0.64 | ||
| VI (High spin) | 0.92 | 0.78 | R* | |
| VI (Low spin) | 0.75 | 0.67 | R | |
| VIII (High spin) | 1.06 | 0.92 | C | |
| 3 | IV (High spin) | 0.63 | 0.49 | * |
| V | 0.72 | 0.58 | ||
| VI (High spin) | 0.785 | 0.645 | R* | |
| VI (Low spin) | 0.69 | 0.55 | R | |
| VIII (High spin) | 0.92 | 0.78 | ||
| 4 | VI | 0.725 | 0.585 | R |
| 6 | IV | 0.39 | 0.25 | R |
| R, From r3 vs V plots. |
| C, Calculated from bond length - bond strength equations. |
| E, Estimated. |
| *, Most Reliable. |
| M, From Metallic Oxides. |
| A, Ahrens (1952) Ionic radius. |
| P, Pauling's (1960) Crystal Radius. |
| 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)  |
|
| 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° | |