Answer: Glass.
- A Diamond
- B Glass
- C Graphite
- D Copper
Correct answer: B. Glass
Explanation: Glass has only short-range order and no sharp melting point, so it is amorphous. Diamond, graphite and copper are crystalline.
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.