Cerium (Ce)
| Atomic Number | 58 |
|---|---|
| Atomic Mass | 140.1161 u |
| Category | Lanthanide |
| Electron Config | [Xe] 4f¹ 5d¹ 6s² |
| Appearance | silvery white |
| Density (STP) | 6689 g/L |
| Melting Point | 1068 K |
| Boiling Point | 3716 K |
| Electronegativity | 1.12 (Pauling) |
| Ionization Energy | 534.4 kJ/mol |
| Atomic Radius | 185 pm |
| Crystal Structure | Simple Hexagonal |
| Discovered By | Martin Heinrich Klaproth (1803) |
Brief Introduction
Cerium (Ce) is a soft, silvery, ductile rare earth metal that is the most abundant of the rare earth elements. It tarnishes readily in air and ignites when scratched with a knife. Key details about Cerium (Ce) are as follows:
Uses: Used in catalytic converters (reduces emissions), glass polishing compounds, self-cleaning ovens (cerium oxide catalyst), lighter flints (ferrocerium), carbon arc lighting, and as a diesel fuel additive to reduce emissions.
Production/Extraction: Extracted from monazite and bastnäsite ores. China, United States, and Brazil are major sources. Most abundant rare earth element, comprising about 50% of rare earth content in ores.
History: Discovered in 1803 by Jöns Jakob Berzelius and Wilhelm Hisinger in Sweden, and independently by Martin Heinrich Klaproth in Germany. Named after the asteroid Ceres, discovered two years earlier.
Health Effects & Safety: Low toxicity but cerium compounds can be irritating. Cerium oxide nanoparticles are being studied for medical applications. Metallic cerium is pyrophoric and ignites easily.
Price/Market: Relatively inexpensive among rare earths due to abundance. Large-scale use in catalysts and polishing drives demand. Supply generally stable.
Properties: Most abundant rare earth, soft and ductile, ignites easily when scratched, exhibits +3 and +4 oxidation states (unusual for lanthanides), strong reducing agent, and forms cerium oxide (ceria) which is an excellent polishing agent.