Given below are two statements: Statement I : The third ionization enthalpy of Magnesium is greater than the corresponding third ionization enthalpy of Aluminum. Statement II : Among the isoelectronic species S ²⁻ , Cl ⁻ , K ⁺ and Ca ²⁺ , the ionic radius of Ca ²⁺ is the largest. In the light of the above statements, choose the correct answer from the options given below:

Step-by-step solution

Statement I: The electronic configuration of Mg is [ Ne ] 3 s ² and that of Al is [ Ne ] 3 s ² 3 p ¹ . After removing two electrons, Mg ²⁺ acquires a stable noble gas configuration [ Ne ] , whereas Al ²⁺ has the configuration [ Ne ] 3 s ¹ . Removing a third electron from the stable noble gas core of Mg ²⁺ requires significantly more energy than removing the 3 s ¹ electron from Al ²⁺ . Thus, the third ionization enthalpy of Mg is greater than that of Al . Statement I is true. Statement II: The species S ²⁻ , Cl ⁻ ,