An element has a face-centred cubic (fcc) structure with a cell edge of a. The distance between the centres of two nearest tetrahedral voids in the lattice is:
- (A)✓ Correct
- (B)
- (C)
- (D)a
Answer: (A)
Solution
In an fcc lattice the tetrahedral voids sit at the centres of the eight small cubes of edge into which the unit cell divides. The two nearest voids are the centres of two edge-sharing small cubes, so the line joining them is just one small-cube edge long. That distance is .
JEE Main · 2019 · 12 Apr 2019 · Shift 1 · Single correct option