which of the following are true ?

Options

A. In NaCl crystals , ` Na^(+)` ions are present in all the octahedral voids.
B. In ZnS ( zinc blende) , ` Zn^(2+)` ions are present in alternate tetrahedral voids.
C. In ` CaF_(2), F^(-)` ions occupy half the octahral voids .
D. In ` Na_(2)O, O^(2-)` ions occupy half the octahedral voids.

Explanation

Only (d) is not true because in ` Na_(2)O, O^(2-)` ions are present in close packing and `Na^(+)` ions occupy all the tetrahedral voids.