Answer: 176.8 pm.
- A 125 pm
- B 176.8 pm
- C 216.5 pm
- D 250 pm
Correct answer: B. 176.8 pm
Explanation: For FCC: r = a√2/4 = 500 × 1.414 / 4 = 707.1 / 4 ≈ 176.8 pm.
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.