Which property of the alkaline earth metals increases with their atomic number?

1. Hydroxides: The lattice energy decreases more rapidly than the hydration energy as the cation size increases down the group. Thus, the solubility of hydroxides increases down the group (${\text{Mg(OH)}}_2<\cdots <{\text{Ba(OH)}}_2$).2. Sulphates: Solubility decreases down the group.3. Electronegativity/IE: Both decrease down the group as atomic size increases.