Ionisation Enthalpy: Due to higher nuclear charge in alkaline earth metals, Electron in alkali earth metals are bounded tightly and thus more energy is required to take them out. Thus, Alkaline Earth metals have more Ionisation Enthalpy.

Basicity of Oxides: Alkali metals oxides are generally more basic than alkaline earth metals.

Solubility of hydroxides: Due to lower ionisation enthalpy, alkali metals are more electropositive and thus are more soluble in water.