Same chapter3 marksDifficulty: Medium
How many atoms are there in a face-centred cubic unit cell?
Solid State
3 marksDifficulty: Medium
Distinguish between Schottky and Frenkel defects and state the effect of each on density.
Original Khojo Papers practice question — not from a past board paper.
Answer
A Schottky defect is a pair of vacancies, one cation and one anion, which lowers the density of the crystal. A Frenkel defect is the displacement of a smaller ion, usually the cation, from its lattice site to an interstitial site, which leaves the density unchanged.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
Schottky defects appear where the ions are of similar size and Frenkel defects where they differ greatly.
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