The lanthanide contraction is responsible for the fact that ________.
A)Zr and Y have about the same radius
B)Zr and Nb have similar oxidation states
C)Zr and Hf have about the same radius
D)Zr and Zn have similar oxidation states
E)Zr and Hf have the same oxidation states

Question

Quizplus · Accepted Answer

The lanthanide contraction is the phenomenon in which there is a relatively small change in atomic radii as you go from one lanthanide element to the next because the added electrons go into the 4f orbitals. This contraction results in elements in the row following the lanthanides having smaller atomic radii than expected based on periodic trends. As a result, Zr (a element in the row following the lanthanides) has a smaller atomic radius than expected, and its radii is similar to that of Hf (the element directly below it), which is why choice C is the correct answer.

The Lanthanide Contraction Is Responsible for the Fact That ________