Answer: 6, octahedral.
- A 4, tetrahedral
- B 6, octahedral
- C 8, cubic
- D 3, trigonal planar
Correct answer: B. 6, octahedral
Explanation: A radius ratio in the range 0.414 to 0.732 corresponds to a coordination number of 6 and octahedral geometry.
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.