| Boron | |
| Electrons per shell | 2,3 |
| Electron Configuration | 1s2 2s2 2p1 |
| Ground state | 2P°1/2 |
| Atomic Volume | 4.6 cm3 mol-1 |
| Electronegativity | 2.04 |
| Magnetic ordering | Non-magnetic |
| Mass magnetic susceptibility | -8.7 x 10-9 |
| Molar magnetic susceptibility | -9.41 x 10-11 |
| Speed of sound | 16200 m s-1 |
 Thermal Properties |
|
| Enthalpy of Atomization | 573.2 kJ mol-1 @25°C |
| Enthalpy of Fusion | 22.2 kJ mol-1 |
| Enthalpy of Vaporisation | 504.5 kJ mol-1 |
| Heat Capacity | 11.087 J mol-1 K-1 |
| Thermal Conductivity | 27.4 W m-1 K-1 |
| Thermal Expansion | 5 - 7 μm m-1 K-1 |
| Hardness |
|
| Mohs hardness | 9.3 |
| Vickers hardness | 49000 MPa |
| Elastic Properties |
|
| Bulk modulus | 185 GPa |
| Electrical Properties |
|
| Electrical resistivity | 1.5 x 104 Ω m |
| Electrical conductivity | ? 106/cm Ω |
| Chemical Properties |
|
| Electrochemical Equivalent | 0.1344 g Ah-1 |
| Electron Work Function | 4.45 eV |
| Valence Electron Potential (-eV) | 190 |
| Ionization Potential | |
 First
|
8.298 |
| Second
|
25.154 |
| Third
|
37.93 |
| Energy Levels |
|
| Kα1 (intensity 100) |
0.1833 KeV |
| Atomic Radii |
|
| Empirical
|
85 pm |
| Bohr Radius
|
87 pm |
| Covalent Radius
|
82 pm |
| Van der Waals
|
No data. |
| Triple covalent
|
73 pm |
| Metallic
|
No data. |
| Oxidation States |
|
| Main
|
B+3 |
| Other
|
|
Ionisation Energies (kJ mol-1)  |
|
| M - M+ |
800.6 |
| M+ - M2+ |
2427 |
| M2+ - M3+ |
3660 |
| M3+ - M4+ |
25025 |
| M4+ - M5+ |
32822 |
| Covalent Bonds (kJ mol-1) |
|
| B-H
|
381 |
| B-H-B
|
439 |
| B-C
|
372 |
| B-O
|
523 |
| B-F
|
644 |
| B-Cl
|
444 |
| B-B
|
335 |
| Vapour Pressure |
||||||
| P (Pa) | 1 | 10 | 100 | 1K | 10K | 100K |
| T (K) | 2348 | 2562 | 2822 | 3141 | 3545 | 4072 |
| Crystal Structure |
|
| Structure
|
Rhombohedral |
 |
a = 506 pm |
| b = 506 pm | |
| c = 506 pm | |
| α = 58.06° | |
| β = 58.06° | |
| γ = 58.06° | |