The `ZnS` structure can be obtained from the

Options

A. rock salt structure by replacing the `Na^(+)` and `Cl^(-)` ions of each basis with one `Zn` atoms and one `S` atom respectively
B. fullferene structure by replacing the two `C` atoms of each basis with one `Zn` atoms and one `S` atom.
C. graphite structure by replacing two `C` atoms of each basis with one `Zn` atom and one `S` atom respectively.
D. diamond structure by replacing the two `C` atoms of each basis with one `Zn` atom and one `S` atom respectively.

Answer

4

Explanation

Diamond structure is similar to that of sphalerite ( or Zinc blende) .In a unit cell of zinc blende ,sulphide ions are at the corners and at the centre of each faces of the unit cell.The position of the Zinc ions can be described if we imagine the unit cell divided into eight cubic parts ,or subcubes,Zinc ions are at the centres of alterante subcubes,the number of `S^(2-)` ions per unit cell is four `(8 "corner ions" xx(1)/(8)+6"face ions")xx(1)/(2)` and the number of `Zn^(2+)` ions is four (All the completely within the unit cell).
Thus ,there are equal number of `Zn^(2+)` and `S^(2-)` ions as expected by the formula `ZnS`.Diamond structure is obtained if each `Zn^(2+)` ion and each `S^(2-)` ion is replaced by `C` atoms.