Answer: 52.4%.
- A 52.4%
- B 68%
- C 74%
- D 100%
Correct answer: A. 52.4%
Explanation: Simple cubic has only 1 atom per cell; the spheres only touch along the edge. The packing efficiency is (π/6) × 100 ≈ 52.4%.
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.