Answer: 5.
- A 2
- B 4
- C 5
- D 6
Correct answer: C. 5
Explanation: Contribution = 8 x 1/8 (corners) + 6 x 1/2 (faces) + 1 (body centre) = 1 + 3 + 1 = 5 atoms per unit cell.
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.