Read the Assertion and Reason below and choose the correct option. — Solid State Chemistry Question

💡 Solution & Explanation

The maximum radius of an atom that can fit in an octahedral void is larger ($0.414R$) than that for a tetrahedral void ($0.225R$). Occupying octahedral voids leads to a substantially greater increase in packing efficiency than occupying tetrahedral voids, making the Assertion false. The Reason is true as an FCC unit cell contains 8 tetrahedral voids and 4 octahedral voids. Therefore, correct answer is D.