Lanthanide

Elements with atomic numbers 57-70

A lanthanide is any of the 15 metallic chemical elements with atomic numbers 57–71, from lanthanum through lutetium. In the periodic table, the first fourteen (up to ytterbium) fill the 4f orbitals. Lutetium (element 71) is also often considered a lanthanide, despite being a d-block element and a transition metal.

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