Question

Identify the incorrect statement among the following

• A. Shielding power of 4f electrons is quite weak
• B. There is a decrease in the radii of the atoms or ions as one proceeds from La to Lu
• C. Lanthanoid contraction is the accumulation of successive shrinkages
• D. As a result of lanthanoid contraction, the properties of 4d series of the transition elements have no similarities with the 5d series of elements

Answer 1

The correct option is D

As a result of lanthanoid contraction, the properties of 4d series of the transition elements have no similarities with the 5d series of elements

The regular decrease in the radii of lanthanide ions from $L{a}^{3+}$ to $L{u}^{3+}$ is known as lanthanide contraction. It is due to the greater effect of the increased nuclear charge as opposed to progressively weakening shielding of valence electrons. As a consequence, the atomic radii of 4d and 5d elements down the group become quite similar due to Lanthanoid contraction. They also exhibit similar properties in some cases.