Write any one consequence of lanthanoid contraction.

Explanation

The steady decrease in the size of the atoms or ions from lanthanum to lutetium is known as lanthanide contraction. As the atomic number increašes in the lanthanide series, the new electrongoes to the inner 4 f orbitals. The shielding effect of a 4f electron is poor. As a result. the atraction of the outer electrons by the nucleus increases and this tends to a decrease in the-size. Due to lanthanidé contraction, the lanthanides have similar atomic and ionic sizes. Thus, they.occur together .afid the separation becomes very difficult.