La - Lanthanum

Lanthanum is a soft, malleable, silvery-white metallic element that is the first member of the lanthanide series in the periodic table, with the symbol La and atomic number 57. Its physical and chemical properties are characteristic of the rare earth elements

Physical Characteristics

• Appearance: Silvery-white, soft, malleable metal.
• Atomic Weight: Approximately 138.90547 u.
• Melting Point: 920°C (1688°F).
• Boiling Point: 3464°C (6267°F).
• Density: 6.162 g/cm³ at room temperature.

Applications

1. Catalysis: Lanthanum is a key component in various catalysts used for refining petroleum. It’s particularly important in fluid catalytic cracking (FCC) catalysts, which help break down heavy hydrocarbon molecules into gasoline, diesel, and other products.
2. Electronics and Optics: Lanthanum is used in the manufacturing of special optical glasses, including camera and telescope lenses, to improve clarity and focusing ability by reducing optical aberrations. Its compounds enhance the refractive index and dispersion of glasses without significantly increasing weight or density.
3. Battery Technology: Lanthanum is used in nickel-metal hydride (NiMH) rechargeable batteries, commonly found in hybrid vehicles, due to its ability to store hydrogen and improve battery capacity and performance.

Compounds

1. Lanthanum Oxide (La2O3): Used in optical applications to make special glasses with high refractive index and low dispersion. Also serves as a catalyst in some chemical reactions and is used in the production of ceramics and phosphors.
2. Lanthanum Fluoride (LaF3): Applied in fluoride glass optical fibers and in making lenses with high optical clarity. It’s also used in phosphors and scintillators.
3. Lanthanum Carbonate (La2(CO3)3): Prescribed for medical use to treat hyperphosphatemia by binding to phosphate in the digestive tract. It’s utilized in water treatment as well.

Basics on Boron-Wikipedia