Answer: Unit cell.
- A Atom
- B Molecule
- C Unit cell
- D Crystal system
Correct answer: C. Unit cell
Explanation: The unit cell is the smallest structural unit that, when repeated in three dimensions, generates the entire crystal.
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.