Answer: 3 (ABC).
- A 2 (AB)
- B 3 (ABC)
- C 4 (ABCD)
- D 6 (ABCABC)
Correct answer: B. 3 (ABC)
Explanation: CCP (cubic close packing) has the stacking sequence ABCABC..., meaning 3 distinct layer positions before the pattern repeats. HCP has ABABAB... (2 positions).
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.