The type of defect in solid is — Solid State Chemistry Question

💡 Solution & Explanation

The observed density ($20 \text{ kg/m}^3$) is much higher than the theoretical density ($5.0 \text{ kg/m}^3$). Vacancy defects (like Schottky) lower density, while Frenkel doesn't change it. A significant density increase strongly points to an impurity defect containing heavier substitute atoms or interstitials. Therefore, correct answer is D.