Lanthanum

Lanthanum is a chemical element classified as a rare earth metal, appearing silver to gray in color. It is soft, malleable, and reacts easily with water and air. Lanthanum is mainly used in making camera lenses, LEDs, and certain types of batteries due to its unique optical and electronic properties. It also plays a role in research and various high-tech applications. Despite being called "rare," it is relatively abundant in the Earth's crust but is often found combined with other elements, making extraction and purification important for its industrial use.