Lanthanides contraction is a reduction of metal and ion diameters from lanthanum to lutetium and it is caused by a core charge growth inside the same shell. Elements which in the periodic system of elements come after lanthanides have, because of lanthanides contraction, smaller diameter than they should have according to their position in the periodic system of elements.
Generalic, Eni. "Lanthanides contraction." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. 14 Apr. 2025. <https://glossary.periodni.com>.
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