Statement-1 : The ratio of Zn^2+ and F^(-) per unit cell of ZnS and CaF_2 is 1 :2 Statement-2 : In ZnS,Zn^2+ ions occupy alternate tetrahedral voids and in CaF_2, F^(-) ions occupy all the tetrahedral voids of FCC unit cell.

Statement-1 : The ratio of Zn^2+ and F^(-) per unit cell of ZnS and Ca

1.	Statement-1 : The ratio of Zn^2+ and F^(-) per unit cell of ZnS and CaF_2 is 1 :2 Statement-2 : In ZnS,Zn^2+ ions occupy alternate tetrahedral voids and in CaF_2, F^(-) ions occupy all the tetrahedral voids of FCC unit cell.
Answer» Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-1 Statement-1 is True, Statement-2 is True, Statement-2 is NOT a correct explanation for Statement-1 Statement-1 is True, Statement-2 is False. Statement-1 is False, Statement-2 is True. Solution :In ZnS type (Zinc blende) (AB type) (4:4 coordination NUMBER COMPOUND): `CaF_2` [Flourite structure] [`AB_2` type] (8:4 coordination number compound): `S^(2-)` ion from the FCC lattice. `toZn^(2+)` ion occupy alternate (non adjacent) four tetrahedral void. `Ca^(2+)` ion from the FCC lattice. `to F^(-)` ion occupy all tetrahedral voids.