Cerium
From The Encyclopedia of Earth
September 29, 2008, 8:54 pm
| Topics: |
| Previous Element: Lanthanum Next Element: Praseodymium |
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| Physical Properties | ||
|---|---|---|
| Color | silvery-white | |
| Phase at Room Temp. | solid | |
| Density (g/cm3) | 6.773 | |
| Hardness (Mohs) | --- | |
|
Melting Point (K) |
1071.2 | |
|
Boiling Point (K) |
3743 | |
| Heat of Fusion (kJ/mol) | 8.9 | |
| Heat of Vaporization (kJ/mol) | 398 | |
| Heat of Atomization (kJ/mol) | 419 | |
| Thermal Conductivity (J/m sec K) | 11.3 | |
| Electrical Conductivity (1/mohm cm) | 13.333 | |
| Source | Monazite (phosphate), bastnaesite | |
| Atomic Properties | ||
| Electron Configuration | [Xe]6s24f15d1 | |
|
Number of Isotopes |
44 (4 natural) | |
| Electron Affinity (kJ/mol) | 50 | |
| First Ionization Energy (kJ/mol) | 527.4 | |
| Second Ionization Energy (kJ/mol) | 1047 | |
| Third Ionization Energy (kJ/mol) | 1949 | |
| Electronegativity | 1.12 | |
| Polarizability (Å3) | 29.6 | |
| Atomic Weight | 140.12 | |
| Atomic Volume (cm3/mol) | 20.7 | |
| Ionic Radius2- (pm) | --- | |
| Ionic Radius1- (pm) | --- | |
| Atomic Radius (pm) | 182 | |
| Ionic Radius1+ (pm) | --- | |
| Ionic Radius2+ (pm) | --- | |
| Ionic Radius3+ (pm) | 115 | |
| Common Oxidation Numbers | +3, +4 | |
| Other Oxid. Numbers | +2 | |
| Abundance | ||
| In Earth's Crust (mg/kg) | 6.65x101 | |
| In Earth's Ocean (mg/L) | 1.2x10-6 | |
| In Human Body (%) | 0.00006% | |
| Regulatory / Health | ||
| CAS Number | 7440-45-1 | |
| 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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