In the cubic close packing, the unit cell has ......... .

1. 4 tetrahedral voids each of which is shared by four adjacent unit cells.
2. 4 tetrahedral voids within the unit cell.
3. 8 tetrahedral voids each of which is shared by four adjacent unit cells.
4. 8 tetrahedral voids within the unit cells.

HINT: Number of tetrahedral void = 2 × number of octahedral void
Explanation: In the cubic close packing the unit cell has 8 tetrahedral voids within it and are located at each eight smaller cube of an unit cell.