|
|
| Radium | |
| Electron Configuration | 2,8,18,32,18,8,2 |
| Electron Configuration | [Rn] 7s2 |
| Ground state | 1S0 |
| Atomic Volume | 45.2 g/cm3 |
| Electronegativity | 0.9 |
| Magnetic ordering | Non-magnetic |
 Thermal Properties |
|
| Enthalpy of Atomization | 163 kJ mol-1 @25°C |
| Enthalpy of Fusion | 7.15 kJ mol-1 |
| Enthalpy of Vaporisation | 136.7 kJ mol-1 |
| Heat Capacity | No data. |
| Thermal Conductivity | 18.6 W m-1 K-1 |
| Thermal Expansion | No data. |
| Electrical Properties |
|
| Electrical resistivity | 1.00 x 10-6 Ω m |
| Electrical conductivity | No data. |
| Chemical Properties |
|
| Electrochemical Equivalent | 4.2165 g Ah-1 |
| Valence Electron Potential (-eV) | 20.1 |
| Ionization Potential | |
 First
|
5.279 |
| Second
|
10.148 |
| Energy Levels |
|
| Kα1 (intensity 0) |
88.47 KeV |
| Kα2 (intensity 0) |
85.43 KeV |
| Kβ1 (intensity 0) |
100.13 KeV |
| Lα1 (intensity 100) |
12.3397 KeV |
| Lα2 (intensity 10) |
12.1962 KeV |
| Lβ1 (intensity 38) |
15.2358 KeV |
| Lβ2 (intensity 14) |
14.8414 KeV |
| Lβ3 (intensity 2) |
15.4436 KeV |
| Lβ4 (intensity 2) |
14.7465 KeV |
| Lγ1 (intensity 8) |
17.849 KeV |
| Lγ2 (intensity 2.7) |
18.1708 KeV |
| Lγ3 (intensity 2) |
13.658 KeV |
| Ll (intensity 6) |
10.6247 KeV |
| Atomic Radii |
|
| Empirical
|
215 pm |
| Bohr Radius
|
No data. |
| Covalent Radius
|
No data. |
| Van der Waals
|
No data. |
| Triple covalent
|
159 pm |
| Metallic
|
No data. |
| Ionic Radii (Å) |
||||
| Charge | Coordination | Crystal | Ionic | Key |
| 2 | VIII | 1.62 | 1.48 | R |
| XII | 1.84 | 1.7 | 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
|
Ra+2 |
| Other
|
|
Ionisation Energies (kJ mol-1)  |
|
| M - M+ |
509.3 |
| M+ - M2+ |
979 |
| M2+ - M3+ |
3300 |
| M3+ - M4+ |
4400 |
| M4+ - M5+ |
5700 |
| M5+ - M6+ |
7300 |
| M6+ - M7+ |
8600 |
| M7+ - M8+ |
9900 |
| M8+ - M9+ |
13500 |
| M9+ - M10+ |
15100 |
| Vapour Pressure |
||||||
| P (Pa) | 1 | 10 | 100 | 1K | 10K | 100K |
| T (K) | 819 | 906 | 1037 | 1209 | 1446 | 1799 |
| Crystal Structure |
|
| Structure
|
Body centred cubic |
 |
a = 514.8 pm |
| b = 514.8 pm | |
| c = 514.8 pm | |
| α = 90° | |
| β = 90° | |
| γ = 90° | |