In `CsCl` the number of formula units per unit cell is

Options

A. `2`
B. `4`
C. `6`
D. `12`

Answer

1

Explanation

Caesium chloride consists of positive ions `(Cs^(+))` ion and one negative ions `(CI^(-))` of about equal size arranged in a cubic array.There are chloride ions at each cornor of the cube and a caesium ion at the centre.Alternative the unit cell may be taken to have caesium ions at the corners of a cube and a chloride ion at the centre.
In either case the unit cell contains one `Cs^(+)` ion and one `CI^(-)` ion:`(1)/(8)Cl^(-)` ion (or `(1)/(8)Sc^(+)`ion) at each of eight corners plus `Cs^(+)` ion (or more `CI^(-)` ion ) at each of the unit cell.