Practice question

Given: Which lanthanoid ion has a 4f⁷ configuration and exhibits paramagnetism? These values define the system as per NCERT data. Formula: Gd (Z = 64) forms Gd^{3+ with 4f⁷, having 7 unpaired electrons, making it paramagnetic.. 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.