Rare earth element definitions

rare earth element

rare earth metal. A metallic element that belongs to Group 3B or to the lanthanide series.
Found on http://antoine.frostburg.edu/chem/senese/101/glossary/r.shtml

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Rare earth element

As defined by IUPAC, a rare earth element (REE) or rare earth metal is one of a set of seventeen chemical elements in the periodic table, specifically the fifteen lanthanides plus 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 ...
Found on http://en.wikipedia.org/wiki/Rare_earth_element

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rare-earth element

any of a large family of chemical elements consisting of the lanthanoids (the 15 elements from lanthanum to lutetium, atomic numbers 57–71) and, ... [6 related articles]
Found on http://www.britannica.com/eb/a-z/r/13

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rare-earth element

Alternative name for lanthanide
Found on https://www.encyclo.co.uk/local/21221

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