Question

Define Lanthanoid contraction.

Answer 1

Lanthanoid contraction

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Nuclear charge increase by +1 in lanthanides and actinides so atomic size of these elements slightly decrease.

It is known as Lanthanoid contraction.

Answer 2

Definition of lanthanide contraction:-

The decrease in size (as of radii of atoms or ions or of atomic volumes) with increasing atomic number of the metals of the lanthanide series

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