rare-earth elements

Definitions

Electronics

  • A series of elements, generally considered to range from atomic number 57 (lanthanum) or 58 (cerium), through 71 (lutetium), inclusive. They have related chemical properties, including high reactivity. Such elements are not rare, and frequently occur together. Also called rare earth metals, rare earth (1), or lanthanides.
  • synonymrare-earth metals
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