Question

Which of the following is not a consequence of the Lanthanoid contraction?

• A. 5d series elements have higher ${IE}_1$ than 3d or 4d series
• B. $Zr$ and $Hf$ have a comparable size
• C. $Zr$ and $Hf$ occurs together in the earth crust in their minerals
• D. High density of the period 6 elements

Answer 1

The correct option is D High density of the period 6 elements

Due to lanthanoid contraction, the atomic radii of the elements which follow lanthanum (Hf, Ta, etc.) are similar to that of the elements of the previous period.

But lanthanoid contraction has nothing to do with high density of all the period 6 elements.