Chemistry - Solid State Question with Solution | TestHub

Schottky defect is a type of point defect in a crystal lattice where an equal number of cations and anions are missing from their normal lattice sites.

Since ions are missing from the crystal, the overall mass decreases while the volume remains unchanged, leading to a decrease in the density of the substance.

Electrical neutrality is maintained because the number of missing positive and negative charges is equal.

This defect is typically found in ionic compounds where the sizes of the cation and anion are almost similar (e.g., NaCl, KCl).

The defect where smaller cations occupy interstitial sites is known as the Frenkel defect.

Answer: The density of a substance decreases.