Answer: M 3 O.
- A M<sub>2</sub>O
- B M<sub>3</sub>O
- C MO
- D M<sub>2</sub>O<sub>3</sub>
Correct answer: B. M<sub>3</sub>O
Explanation: For N oxide ions there are N octahedral and 2N tetrahedral voids; filling all gives 3N metal ions, so M:O = 3:1, i.e. M<sub>3</sub>O.
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.