Question

Which of the following defects decrease the density? I. Interstitial defect $\quad\quad$II. Vacancy defect III. Frenkel defect $\quad\quad$IV. Schottky defect

• A. I and IV
• B. II and IV
• C. III and IV
• D. I, II and III

Answer 1

Answer: (B)

II and IV

Answer 2

In vacancy defect and Schottky defect, some lattice sites are vacant. Thus, mass decreases but volume remains the same. Hence, density decreases.