Among the following oxides, which has the maximum lattice energy? — Periodic Table and Periodicity Chemistry Question

💡 Solution & Explanation

Step 1: Lattice energy (U) of ionic crystals is directly proportional to the charges on the ions and inversely proportional to the interionic distance (r_+ + r_-). Step 2: In these alkaline earth metal oxides, all have the same ionic charges (+2 and -2). Thus, lattice energy depends entirely on the size of the cation. Step 3: Since Mg^2+ is the smallest cation among the alkaline earth metals listed, MgO has the shortest interionic distance and therefore possesses the maximum lattice energy (option a).