CERIUM

Cerium, a soft, silvery and ductile metal, is the most abundant of the rare earth elements. It also has numerous applications. For example, cerium (III) oxide is used as a catalyst for the oxidation of CO emissions from motor vehicles, while cerium oxide (IV) is used for precision polishing of optical componets. Cerium compounds are also used in producing glass. Cerium can also be add to aluminum, iron and magnesium alloys to their properties.

A ductile malleable gray element of the lanthanoid series of metals. It occurs in association with other lanthanoids in many minerals, including monazite and bastnasite. The metal is reactive; it reacts with water and tarnishes in air. It is used in several alloys (especially for lighter flints), as a catalyst, and in compound form in carbon-arc searchlights, etc., and in the glass industry.