Promethium
From The Encyclopedia of Earth
December 6, 2006, 9:18 pm
| Topics: |
| Previous Element: Neodymium Next Element: Samarium |
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| Physical Properties | ||
|---|---|---|
| Color | silvery-white | |
| Phase at Room Temp. | solid | |
| Density (g/cm3) | 7.2 | |
| Hardness (Mohs) | --- | |
|
Melting Point (K) |
1353.2 | |
|
Boiling Point (K) |
--- | |
| Heat of Fusion (kJ/mol) | 12.5 | |
| Heat of Vaporization (kJ/mol) | --- | |
| Heat of Atomization (kJ/mol) | 301 | |
| Thermal Conductivity (J/m sec K) | 17.9 | |
| Electrical Conductivity (1/mohm cm) | 0 | |
| Source | Synthetic | |
| Atomic Properties | ||
| Electron Configuration | [Xe]6s24f5 | |
|
Number of Isotopes |
47 (0 natural) | |
| Electron Affinity (kJ/mol) | 50 | |
| First Ionization Energy (kJ/mol) | 535.9 | |
| Second Ionization Energy (kJ/mol) | 1052 | |
| Third Ionization Energy (kJ/mol) | 2150 | |
| Electronegativity | 1.15 | |
| Polarizability (Å3) | 30.1 | |
| Atomic Weight | 144.9 | |
| Atomic Volume (cm3/mol) | 20.1 | |
| Ionic Radius2- (pm) | --- | |
| Ionic Radius1- (pm) | --- | |
| Atomic Radius (pm) | 183 | |
| Ionic Radius1+ (pm) | --- | |
| Ionic Radius2+ (pm) | --- | |
| Ionic Radius3+ (pm) | 111 | |
| Common Oxidation Numbers | +3 | |
| Other Oxid. Numbers | --- | |
| Abundance | ||
| In Earth's Crust (mg/kg) | --- | |
| In Earth's Ocean (mg/L) | --- | |
| In Human Body (%) | --- | |
| Regulatory / Health | ||
| CAS Number | 7440-12-2 | |
| OSHA Permissible Exposure Limit (PEL) | No limits | |
| OSHA PEL Vacated 1989 | No limits | |
|
NIOSH Recommended Exposure Limit (REL) |
No limits | |
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Sources: |
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