As defined by IUPAC, rare earth elements or rare earth metals are a collection of seventeen chemical elements in the periodic table, namely scandium, yttrium, and the fifteen lanthanoids. Scandium and yttrium are considered rare earths since they tend to occur in the same ore deposits as the lanthanoids and exhibit similar chemical properties.
The term "rare earth" arises from the minerals from which they were first isolated, which were uncommon ...
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Rare earth element
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Lanthanide
According to the IUPAC terminology, the lanthanoid (previously lanthanide) series comprises the fifteen elements with atomic numbers 57 through 71, from lanthanum to lutetium. All lanthanoids are f-block elements, corresponding to the filling of the 4f electron shell, except for lutetium which is a...