|
|
| Potassium | |
| Electron Configuration | 2,8,8,1 |
| Electron Configuration | [Ar] 4s1 |
| Ground state | 2S1/2 |
| Atomic Volume | 45.46 g/cm3 |
| Electronegativity | 0.82 |
| Magnetic ordering | No data |
| Mass magnetic susceptibility | 6.7 x 10-9 |
| Molar magnetic susceptibility | 2.62 x 10-10 |
| Speed of sound | 2000 m s-1 |
 Thermal Properties |
|
| Enthalpy of Atomization | 89.5 kJ mol-1 @25°C |
| Enthalpy of Fusion | 2.40 kJ mol-1 |
| Enthalpy of Vaporisation | 79.1 kJ mol-1 |
| Heat Capacity | 29.600 J mol-1 K-1 |
| Thermal Conductivity | 102.5 W m-1 K-1 |
| Thermal Expansion | 83.3 μm m-1 K-1 |
| Hardness |
|
| Brinell hardness | 0.363 MPa |
| Mohs hardness | 0.4 |
| Elastic Properties |
|
| Bulk modulus | 3.1 GPa |
| Shear modulus | 1.3 GPa |
| Electrical Properties |
|
| Electrical resistivity | 7 x 10-8 Ω m |
| Electrical conductivity | No data. |
| Chemical Properties |
|
| Electrochemical Equivalent | 1.4587 g Ah-1 |
| Electron Work Function | 2.3 eV |
| Valence Electron Potential (-eV) | 10.4 |
| Ionization Potential | |
 First
|
4.341 |
| Second
|
31.625 |
| Third
|
45.72 |
| Energy Levels |
|
| Kα1 (intensity 100) |
3.3138 KeV |
| Kα2 (intensity 0) |
3.3111 KeV |
| Kβ1 (intensity 13.7) |
3.5896 KeV |
| Lα1 (intensity 100) |
0.2591 KeV |
| Lγ3 (intensity 0) |
0.262 KeV |
| Ll (intensity 100) |
0.2591 KeV |
| Atomic Radii |
|
| Empirical
|
220 pm |
| Bohr Radius
|
243 pm |
| Covalent Radius
|
196 pm |
| Van der Waals
|
275 pm |
| Triple covalent
|
No data. |
| Metallic
|
227 pm |
| Ionic Radii (Å) |
||||
| Charge | Coordination | Crystal | Ionic | Key |
| 1 | IV | 1.51 | 1.37 | |
| VI | 1.52 | 1.38 | ||
| VII | 1.6 | 1.46 | ||
| VIII | 1.65 | 1.51 | ||
| IX | 1.69 | 1.55 | ||
| X | 1.73 | 1.59 | ||
| XII | 1.78 | 1.64 | ||
| 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
|
K+1 |
| Other
|
K-1 (in liquid NH3) |
Ionisation Energies (kJ mol-1)  |
|
| M - M+ |
418.8 |
| M+ - M2+ |
3051.4 |
| M2+ - M3+ |
4411 |
| M3+ - M4+ |
5877 |
| M4+ - M5+ |
7975 |
| M5+ - M6+ |
9649 |
| M6+ - M7+ |
11343 |
| M7+ - M8+ |
11942 |
| M8+ - M9+ |
16964 |
| M9+ - M10+ |
48575 |
| Crystal Structure |
|
| Structure
|
Body centred cubic |
 |
a = 532.8 pm |
| b = 532.8 pm | |
| c = 532.8 pm | |
| α = 90° | |
| β = 90° | |
| γ = 90° | |