The crystalline salts of alkaline earth metals contain more water of crystallisation than the corresponding alkali metal salts. Why ?

Explanation

Due to smaller size and higher nuclear charge , alkaline earth metals have a higher tendency than alkali metals to attract `H_(2)O` molecules and thus contain more water of crystallization than alkali metals . For example, `MgCl_(2) .6H_(2)O` . However , among alkali metals , only lithium because of its small size , forms hydrated salts , i.e., `LiCl.2 H_(2)O`