Which element in group 2 has the highest hydration enthalpy due to its ionic size?
Hydration enthalpy increases with smaller ionic size and higher charge density. Be²⁺ (smallest in group 2) has the highest hydration enthalpy compared to Mg²⁺, Ca²⁺, or Sr²⁺.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Genesis of Periodic Classification - Dobereiner Newlands Mendeleev