Which of the following defects in the crystals may lower the density? — Solid State Chemistry Question

💡 Solution & Explanation

A vacancy defect involves missing atoms from lattice sites, which decreases the total mass without significantly altering the volume, thereby lowering the density. A Schottky defect is specifically a vacancy defect in ionic crystals (missing cation-anion pairs) and definitively lowers density. Therefore, correct answer is B,C.