Question:
In which of the following structures coordination number for cations and
anions in the packed structure will be same?
(i) Cl–ion form fcc lattice and Na+ ions occupy all octahedral voids of the unit cell.
(ii) Ca2+ ions form fcc lattice and F- ions occupy all the eight tetrahedral voids of the unit cell.
(iii) O2– ions form fcc lattice and Na+ions occupy all the eight tetrahedral voids of the unit cell.
(iv) S2– ions form fcc lattice and Zn2+ ions go into alternate tetrahedral voids
of the unit cell.
Solution:
Option (i) Cl–ion form fcc lattice and Na+ ions occupy all octahedral voids of the unit cell is the answer.