|
|
| Barium | |
| Electron Configuration | 2,8,18,18,8,2 |
| Electron Configuration | [Xe] 6s2 |
| Ground state | 1S0 |
| Atomic Volume | 39.24 g/cm3 |
| Electronegativity | 0.89 |
| Magnetic ordering | No data |
| Mass magnetic susceptibility | 1.13 x 10-8 |
| Molar magnetic susceptibility | 1.552 x 10-9 |
| Speed of sound | 1620 m s-1 |
 Thermal Properties |
|
| Enthalpy of Atomization | 175.7 kJ mol-1 @25°C |
| Enthalpy of Fusion | 7.66 kJ mol-1 |
| Enthalpy of Vaporisation | 150.9 kJ mol-1 |
| Heat Capacity | 28.07 J mol-1 K-1 |
| Thermal Conductivity | 18.4 W m-1 K-1 |
| Thermal Expansion | 20.6 μm m-1 K-1 |
| Hardness |
|
| Mohs hardness | 1.25 |
| Elastic Properties |
|
| Bulk modulus | 9.6 GPa |
| Shear modulus | 4.9 GPa |
| Young's modulus | 13 GPa |
| Electrical Properties |
|
| Electrical resistivity | 3.5 x 10-7 Ω m |
| Electrical conductivity | No data. |
| Chemical Properties |
|
| Electrochemical Equivalent | 2.5621 g Ah-1 |
| Electron Work Function | 2.7 eV |
| Valence Electron Potential (-eV) | 21.3 |
| Ionization Potential | |
 First
|
5.212 |
| Second
|
10.004 |
| Energy Levels |
|
| Kα1 (intensity 100) |
32.1936 KeV |
| Kα2 (intensity 50) |
31.8171 KeV |
| Kβ1 (intensity 20.8) |
36.3782 KeV |
| Kβ2 (intensity 6.5) |
37.2524 KeV |
| Kβ3 (intensity 8.9) |
36.2977 KeV |
| Lα1 (intensity 100) |
4.46626 KeV |
| Lα2 (intensity 10) |
4.4509 KeV |
| Lβ1 (intensity 50) |
4.82753 KeV |
| Lβ2 (intensity 18) |
5.1565 KeV |
| Lβ3 (intensity 10) |
4.9272 KeV |
| Lβ4 (intensity 4) |
4.8528 KeV |
| Lγ1 (intensity 6.5) |
5.5311 KeV |
| Lγ2 (intensity 2.6) |
5.7995 KeV |
| Lγ3 (intensity 2) |
4.329 KeV |
| Ll (intensity 4) |
3.9587 KeV |
| Atomic Radii |
|
| Empirical
|
215 pm |
| Bohr Radius
|
253 pm |
| Covalent Radius
|
198 pm |
| Van der Waals
|
No data. |
| Triple covalent
|
149 pm |
| Metallic
|
222 pm |
| Ionic Radii (Å) |
||||
| Charge | Coordination | Crystal | Ionic | Key |
| 2 | VI | 1.49 | 1.35 | |
| VII | 1.52 | 1.38 | C | |
| VIII | 1.56 | 1.42 | ||
| IX | 1.61 | 1.47 | ||
| X | 1.66 | 1.52 | ||
| XI | 1.71 | 1.57 | ||
| XII | 1.75 | 1.61 | C | |
| 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
|
Ba+2 |
| Other
|
|
Ionisation Energies (kJ mol-1)  |
|
| M - M+ |
502.8 |
| M+ - M2+ |
965.1 |
| M2+ - M3+ |
3600 |
| M3+ - M4+ |
4700 |
| M4+ - M5+ |
6000 |
| M5+ - M6+ |
7700 |
| M6+ - M7+ |
9000 |
| M7+ - M8+ |
10200 |
| M8+ - M9+ |
13500 |
| M9+ - M10+ |
15100 |
| Vapour Pressure |
||||||
| P (Pa) | 1 | 10 | 100 | 1K | 10K | 100K |
| T (K) | 911 | 1038 | 1185 | 1388 | 1686 | 2170 |
| Crystal Structure |
|
| Structure
|
Body centered cubic |
 |
a = 502.8 pm |
| b = 502.8 pm | |
| c = 502.8 pm | |
| α = 90° | |
| β = 90° | |
| γ = 90° | |