Question

Lanthanoid contraction can be observed in:

• A. At
• B. Gd
• C. Ac
• D. Lw

Hint:

Lanthanoid contraction is most apparent in Gd due to poor shielding of the nuclear charge by the f-electrons.

Answer 1

The Correct Option is B

Step 1: Lanthanoid contraction refers to the progressive decrease in the size of the lanthanide ions as we move from left to right across the lanthanide series.
Step 2: This contraction is mainly due to the ineffective shielding of the nuclear charge by the f-electrons.
Step 3: Gadolinium (Gd) is the element in the lanthanide series where lanthanoid contraction is most notable due to its electron configuration.