A rare - earth element (REE) or rare - earth metal (REM), as defined by IUPAC, is one of a set of seventeen chemical elements in the periodic table, specifically the fifteen lanthanides, as well as scandium and yttrium. Scandium and yttrium are considered rare - earth elements because they tend to occur in the same ore deposits as the lanthanides and exhibit similar chemical properties. For the same set of mineralogical, chemical, physical (especially electron shell configuration), and related reasons, a broader definition of rare earth elements including the actinides is encountered in some cases. Thorium is a significant component of monazite and other important rare earth minerals, and uranium and decay products are found in others. Both series of elements begin on the periodic table in group 3 under yttrium and scandium.
where are the rare earth metals located on the periodic table
begin on the periodic table in group 3 under yttrium and scandium