Practice question

Given: Which of the following lanthanoids exhibits a +4 oxidation state due to its noble gas configuration? These values define the system as per NCERT data. Formula: Cerium (Ce, Z = 58) forms Ce^{4+ with 4f⁰ (noble gas-like), making it stable in this state.. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Substituting values like 1.2 × 10⁻⁵, 236 J kg⁻¹ K⁻¹, CH₃CH₂NH₂ etc. into the formula and simplifying step by step. Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.