Lanthanum (La)

 History and Discovery
 Lanthanum was discovered in 1839 by Swedish chemist Carl Mosander while studying cerium ores. The name comes from the Greek word "lanthanein," meaning "to hide," as it remained "hidden" within minerals alongside other elements for a long time.

Physical and Chemical Properties

• Soft, silvery-white metal, part of the lanthanoid group (sometimes identified as the element that starts the lanthanoid series).
• Quickly oxidizes in air, typically exhibiting a +3 oxidation state in compounds.
• Density of about 6.15 g/cm³, melting point ~920°C.

Main Applications

• Nickel-Metal Hydride Batteries (NiMH): Lanthanum enhances the capacity and stability of these batteries.
• Optical Glass: Special glasses with lanthanum are used in camera and cinema lenses to improve brightness and clarity.
• Catalysts: Used particularly in petroleum refining (e.g., cracking processes).
• Alloys: Small additions of lanthanum improve the mechanical and corrosion-resistant properties of steel and other metals.

Interesting Facts

• Lanthanum is considered the "elder brother" of all lanthanoids and often marked as the starting point of rare earth elements in the periodic table.
• Lanthanum is more abundant in the Earth's crust than silver but is found in dispersed forms, requiring complex extraction methods.