rare earth elements A group of metallic elements having closesly similar chemical properties. They are mainly trivalent, but otherwise similar to the alkaline earth elements. The group consists of the lanthanide elements with atomic numbers 57 (lanthanum) to 71, plus scandium (21) and yttrium (39). Related category INORGANIC CHEMISTRY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) |