Property of the alkaline earth metals that increases with their atomic number

Step-by-step solution

Electronegativity as well as ionisation energy both usually decrease on moving downward a group with increase in atomic number. The hydroxides and sulphates of alkaline earth metals are ionic solids and the solubility of ionic solids is governed by two factors, viz, lattice energy and hydration energy. For solubility, hydration energy > lattice energy. Hydration energy varies inversely with size, ie, decreases with increase in size. However, lattice energy in case of sulphates, remains almost same with increase in