Q. Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): In a particular point defect, an ionic solid is electrically neutral, even if few of is cations are missing from its unit cells. Reason (R): In an ionic solid, Frenkel defect arises due to dislocation of cation from its lattice site to interstitial site, maintaining overall electrical neutrality. In the light of the above statements, choose the most appropriate answer from the options given below:
A) (A) is not correct but (R) is correct
B) Both (A) and (R) are correct and (R) is the correct explanation of (A)
C) Both (A) and (R) are correct but (R) is not the correct explanation of (A)
D) (A) is correct but (R) is not correct
Explanation
[Solution] Assertion describes the Schottky defect (equal numbers of cations and anions missing), which keeps neutrality; the reason (Frenkel defect) is also true but does not explain the assertion. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.