Question

Which of the following is not a point defect?

• A. Dislocation
• B. Interstitials
• C. Vacancies
• D. Frenkel defect

Hint:

Remember: Point defects involve disruptions at individual lattice points (e.g., vacancies), while line defects involve rows of atoms (e.g., dislocations).

Answer 1

The Correct Option is A

Step 1: Understanding Point Defects Point defects are localized disruptions in the perfect regular arrangement of atoms. Common examples include: - Vacancies: Missing atoms from lattice sites, - Interstitials: Atoms that occupy positions between regular lattice sites, - Frenkel Defect: A combination of a vacancy and an interstitial — an atom moves from its position to an interstitial site. Step 2: Understanding Dislocation - Dislocation is a type of line defect, not a point defect. - It involves a distortion along a line in the crystal lattice, - Most commonly represented by edge or screw dislocations. Step 3: Conclusion Since dislocation involves a line of atoms and not just a single site, it is not a point defect.