Answer: Antiparallel with equal magnitude giving zero net moment.
- A All parallel (same direction)
- B Antiparallel with equal magnitude giving zero net moment
- C Antiparallel with unequal magnitude, giving a small net magnetic moment
- D Completely randomly oriented with no preferred alignment at all
Correct answer: B. Antiparallel with equal magnitude giving zero net moment
Explanation: Antiferromagnetic materials have magnetic moments of equal magnitude arranged antiparallel in adjacent atoms, cancelling each other out so the net magnetic moment is zero. MnO is an example.
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.