The lanthanide contraction results because
A) the shielding effect of the d-electrons is less than that of the f-electrons.
B) the shielding effect of the d-electrons is greater than that of the f-electrons.
C) of the poor shielding effect of the f-electrons and the higher nuclear charge.
D) the d-electrons shield the f-electrons from the nucleus.
E) f-electrons interact more strongly with each other than d-electrons.

Question

Quizplus · Accepted Answer

The lanthanide contraction occurs because of the poor shielding effect of the f-electrons and the higher nuclear charge. The f-electrons are poorly shielded by the inner electrons and therefore experience a stronger attraction to the nucleus. As a result, the atoms of the lanthanides have smaller radii than expected based on their position in the periodic table.

The Lanthanide Contraction Results Because