Praseodymium
From The Encyclopedia of Earth
December 6, 2006, 9:34 pm
| Topics: |
| Previous Element: Cerium Next Element: Neodymium |
| |
| Physical Properties | ||
|---|---|---|
| Color | silvery-white | |
| Phase at Room Temp. | solid | |
| Density (g/cm3) | 6.475 | |
| Hardness (Mohs) | --- | |
|
Melting Point (K) |
1204.2 | |
|
Boiling Point (K) |
3293 | |
| Heat of Fusion (kJ/mol) | 11.3 | |
| Heat of Vaporization (kJ/mol) | 331 | |
| Heat of Atomization (kJ/mol) | 356 | |
| Thermal Conductivity (J/m sec K) | 12.5 | |
| Electrical Conductivity (1/mohm cm) | 14.706 | |
| Source | Monazite (phosphate), bastnaesite | |
| Atomic Properties | ||
| Electron Configuration | [Xe]6s24f3 | |
|
Number of Isotopes |
45 (1 natural) | |
| Electron Affinity (kJ/mol) | 50 | |
| First Ionization Energy (kJ/mol) | 523.2 | |
| Second Ionization Energy (kJ/mol) | 1018 | |
| Third Ionization Energy (kJ/mol) | 2086 | |
| Electronegativity | 1.13 | |
| Polarizability (Å3) | 28.2 | |
| Atomic Weight | 140.91 | |
| Atomic Volume (cm3/mol) | 21.8 | |
| Ionic Radius2- (pm) | --- | |
| Ionic Radius1- (pm) | --- | |
| Atomic Radius (pm) | 182 | |
| Ionic Radius1+ (pm) | --- | |
| Ionic Radius2+ (pm) | --- | |
| Ionic Radius3+ (pm) | 113 | |
| Common Oxidation Numbers | +3 | |
| Other Oxid. Numbers | +2, +4 | |
| Abundance | ||
| In Earth's Crust (mg/kg) | 9.2x100 | |
| In Earth's Ocean (mg/L) | 6.4x10-7 | |
| In Human Body (%) | --- | |
| Regulatory / Health | ||
| CAS Number | 7440-10-0 | |
| OSHA Permissible Exposure Limit (PEL) | No limits | |
| OSHA PEL Vacated 1989 | No limits | |
|
NIOSH Recommended Exposure Limit (REL) |
No limits | |
|
Sources: |
||
