Question

{"given":"The question asks about compounds that exhibit Frenkel defects. Frenkel defect is a type of point defect in ionic crystals where a smaller ion (usually cation) is displaced from its normal lattice site to an interstitial position, creating a vacancy at the original site and an interstitial ion.","key_observation":"Frenkel defects occur in ionic crystals where there is a significant size difference between the cation and anion, with the smaller cation being able to fit into interstitial sites. This defect is commonly observed in compounds like AgBr, ZnS, and AgI because the cations (Ag⁺, Zn²⁺) are much smaller than their respective anions (Br⁻, S²⁻, I⁻), allowing them to move to interstitial positions without causing excessive lattice strain.","option_analysis":[{"label":"(A)","text":"AgBr","verdict":"correct","explanation":"Silver bromide exhibits Frenkel defect because the Ag⁺ ion is much smaller than the Br⁻ ion, allowing Ag⁺ to move from its normal lattice position to interstitial sites."},{"label":"(B)","text":"ZnS","verdict":"correct","explanation":"Zinc sulfide shows Frenkel defect as the Zn²⁺ ion is significantly smaller than the S²⁻ ion, enabling Zn²⁺ to occupy interstitial positions while leaving vacancies at normal sites."},{"label":"(C)","text":"AgI","verdict":"correct","explanation":"Silver iodide exhibits Frenkel defect because the Ag⁺ ion is much smaller than the I⁻ ion, allowing the silver ion to move to interstitial positions in the crystal lattice."},{"label":"(D)","text":"All of these","verdict":"correct","explanation":"This is the correct answer since AgBr, ZnS, and AgI all exhibit Frenkel defects due to the significant size difference between their respective cations and anions."}],"answer":"(D)","formula_steps":[]}