Lanthanum (La)
| Atomic Number | 57 |
|---|---|
| Atomic Mass | 138.905477 u |
| Category | Lanthanide |
| Electron Config | [Xe] 5d¹ 6s² |
| Appearance | silvery white |
| Density (STP) | 6146 g/L |
| Melting Point | 1193 K |
| Boiling Point | 3737 K |
| Electronegativity | 1.1 (Pauling) |
| Ionization Energy | 538.1 kJ/mol |
| Atomic Radius | 195 pm |
| Crystal Structure | Simple Hexagonal |
| Discovered By | Carl Gustaf Mosander (1839) |
Brief Introduction
Lanthanum (La) is a soft, silvery-white rare earth metal that tarnishes rapidly in air and reacts with water. It is the first element in the lanthanide series and gives the series its name. Key details about Lanthanum (La) are as follows:
Uses: Used in camera and telescope lenses (high refractive index glass), fluid catalytic cracking catalysts in petroleum refining, hydrogen storage alloys, carbon arc lighting for movie projectors, and in nickel-metal hydride batteries.
Production/Extraction: Extracted from monazite and bastnäsite ores through ion exchange and solvent extraction. China dominates production. Often produced alongside other rare earth elements.
History: Discovered in 1839 by Carl Gustaf Mosander in Sweden by extracting it from cerium nitrate. Named from Greek "lanthanein" (to lie hidden) because it was hidden in cerium minerals.
Health Effects & Safety: Low to moderate toxicity. Can cause liver damage with chronic exposure. No known biological role. Lanthanum carbonate is used medically to reduce phosphate absorption in kidney disease patients.
Price/Market: Moderate pricing among rare earths. Demand driven by catalysts and battery applications. Supply tied to Chinese rare earth production and export policies.
Properties: Soft and malleable, tarnishes rapidly in air, reacts slowly with water, exhibits +3 oxidation state almost exclusively, pyrophoric when finely divided, and has similar properties to calcium.
← Barium (Ba) · Cerium (Ce) →