in which of the following structures coordination number for cations and anions in the packed structure will be same ?

Options

A. `Cl^(-)` ions form fcc lattice and `Na^(+)` ions occupy all octahedral voids of the unit cell
B. `Ca^(2+)` ions form fcc lattice and `F^(-)` ions occupy all the eight tetrahedral voids of the unit cell.
C. `O^(2-)` ions form fcc lattice and `Na^(+)` ions occupy all the eight tetrahedral voids of the unit cell.
D. `S^(2-)` form fcc lattice and `Zn^(2+)` ions go into alternate tetrahedral voids of the unit cell

Answer

A, D

Explanation

In NaCl, both `Na^(+) and Cl^(-)` ions have six C.N/ (d) is also correct. The C.N of both `Zn^(2+) and S^(2-)` ions are four.