Answer: 2N.
- A N
- B 2N
- C N/2
- D 3N
Correct answer: B. 2N
Explanation: For N spheres in a close-packed structure, there are 2N tetrahedral voids and N octahedral voids.
The three cubic unit cells: Simple Cubic has atoms only at corners; Body-Centred adds one atom at the centre; Face-Centred adds one atom at the centre of each of the 6 faces, giving the highest packing efficiency.
Concept context
Explore the ordered world of crystalline solids: unit cells, packing, defects, and how structure determines electrical and magnetic properties.