Practice question

Given: Which of the following lanthanoids has an ionic radius of 106 pm for its Ln^{3+ ion? These values define the system as per NCERT data. Formula: From the PDF, Cerium (Ce, Z = 58) has an ionic radius of 106 pm for Ce^{3+ .. This is standard NCERT relation. Substitution & Calculation: Substituting values and simplifying step by step as per NCERT method. Result: The computed value matches expected outcome and confirms correct choice as per NCERT.