Given below are four statements regarding s-block elements: (A) The hydration enthalpy of Mg ²⁺ is more negative than that of Na ^+ . (B) The aqueous ionic mobility of alkali metals follows the order Cs ^+ > Rb ^+ > K ^+ > Na ^+ > Li ^+ . (C) The hydrated radius of Be ²⁺ is smaller than that of Ba ²⁺ . (D) The magnitude of hydration enthalpy decreases down the group for alkaline earth metals. Choose the most appropri

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Statement (A) is correct: Alkaline earth metal ions like Mg ²⁺ have a higher charge and smaller size than alkali metal ions like Na ^+ , leading to a higher charge density and a more negative hydration enthalpy. Statement (B) is correct: Smaller bare ions are more extensively hydrated. Thus, Li ^+ has the largest hydrated radius and consequently the lowest ionic mobility in aqueous solution, while Cs ^+ has the highest ionic mobility. Statement (C) is incorrect: Due to its very small bare ionic size, Be ²⁺ is heavi