|
|
| Americium | |
| Electron Configuration | 2,8,18,32,25,8,2 |
| Electron Configuration | [Rn] 5f7 7s2 |
| Ground state | 8S°7/2 |
| Atomic Volume | 17.86 g/cm3 |
| Electronegativity | 1.3 |
| Magnetic ordering | No data |
| Mass magnetic susceptibility | 5.15 x 10-8 |
| Molar magnetic susceptibility | 1.251 x 10-8 |
 Thermal Properties |
|
| Enthalpy of Atomization | 268 kJ mol-1 @25°C |
| Enthalpy of Fusion | 14.4 kJ mol-1 |
| Enthalpy of Vaporisation | 238.5 kJ mol-1 |
| Heat Capacity | 62.7 J mol-1 K-1 |
| Thermal Conductivity | 10 W m-1 K-1 |
| Thermal Expansion | No data. |
| Electrical Properties |
|
| Electrical resistivity | No data. |
| Electrical conductivity | No data. |
| Chemical Properties |
|
| Electrochemical Equivalent | 3.0229 g Ah-1 |
| Valence Electron Potential (-eV) | 44 |
| Ionization Potential | |
 First
|
5.993 |
| Energy Levels |
|
| Lα1 (intensity 100) |
14.6172 KeV |
| Lα2 (intensity 10) |
14.4119 KeV |
| Lβ1 (intensity 38) |
18.852 KeV |
| Lβ2 (intensity 14) |
17.6765 KeV |
| Lβ3 (intensity 2) |
19.101 KeV |
| Lβ4 (intensity 2) |
18.0633 KeV |
| Lγ1 (intensity 8) |
22.0652 KeV |
| Lγ2 (intensity 2.7) |
22.3684 KeV |
| Lγ3 (intensity 2) |
16.79 KeV |
| Ll (intensity 6) |
12.3817 KeV |
| Atomic Radii |
|
| Empirical
|
175 pm |
| Bohr Radius
|
No data. |
| Covalent Radius
|
No data. |
| Van der Waals
|
No data. |
| Triple covalent
|
No data. |
| Metallic
|
173 pm |
| Ionic Radii (Å) |
||||
| Charge | Coordination | Crystal | Ionic | Key |
| 2 | VII | 1.35 | 1.21 | |
| VIII | 1.4 | 1.26 | ||
| IX | 1.45 | 1.31 | ||
| 3 | VI | 1.115 | 0.975 | R |
| VIII | 1.23 | 1.09 | ||
| 4 | VI | 0.99 | 0.85 | R |
| VIII | 1.09 | 0.95 | ||
| 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
|
Am+3 |
| Other
|
Am+2, Am+4, Am+5, Am+6 |
Ionisation Energies (kJ mol-1)  |
|
| M - M+ |
578.2 |
| Vapour Pressure |
||||||
| P (Pa) | 1 | 10 | 100 | 1K | 10K | 100K |
| T (K) | 1239 | 1356 | ||||
| Crystal Structure |
|
| Structure
|
Hexagonal close packed |
 |
a = 346.81 pm |
| b = 346.81 pm | |
| c = 1124.1 pm | |
| α = 90° | |
| β = 90° | |
| γ = 120° | |