Question

In Zinc blende structure:
A. Zinc ions occupy half of the tetrahedral sites
B. Each $Z{{n}^{2+}}$ ion is surrounded by six sulphide ions.
C. Each ${{S}^{2-}}$ ion is surrounded by six $Z{{n}^{2+}}$ ions.
D. It has FCC structure

Answer 1

Zinc blende is represented by the formula $ZnS$ and it is a mineral which is chief ore of zinc. It is in the crystalline form which consists of zinc sulfide ions and it has a diamond type network and at different temperatures it becomes wurtzite structure.

Complete answer:
Zinc sulfide is one of the unique compounds which forms two types of crystalline structures. These two forms also known as polymorphs are wurtzite and zinc blende which can also be known by the name sphalerite.
It is characterized by single bonds between each atom and maintains the structure as 1:1 ratio of zinc to sulfur. The ionic radius for $Z{{n}^{2+}}$ is 74pm and for ${{S}^{2-}}$ is 190pm. So we can say that the ratio between cationic and anionic radii in zinc blend is 0.39 pm. This implies a tetrahedral ion arrangement in which four sulfur atoms surround each zinc atom and four zinc atoms surround each sulfur atom. The coordination number i.e. the number of electron pairs donated to a metal by its ligands is four for both zinc and sulfur. Zinc blende is characterized as a cubic closest packing (ccp) which is also known as face-centered cubic i.e. fcc structure.

Hence we can say that option (D) is correct.

Note: The difference between wurtzite and zinc blender can be dependent on the different arrangements of layers of ions. Wurtzite has a hexagonal structure whereas the structure of zinc blender is cubic in nature.