In a solid `AB` having the `NaCl` structure, A atom occupies the corners of the cubic unit cell. If all the face-centred atoms along one of the axes are removed, then the resultant stoichiometry of the solid is

Options

A. `AB_(2)`
B. `A_(2)B`
C. `A_(4)B_(2)`
D. `A_(2)B_(4)`

Answer

a

Explanation

The were `6A` atoms on the face - centers .Removing face- centers atoms along one of the ases meats remove of `2A` atoms
Now number of A atoms per unit cell
`=underset(("corners"))(8xx(1)/(8))+underset(("face-centred"))(4xx(1)/(2)=3`
Number of B atoms per unit cell
`=underset(("edge centred"))(12xx(1)/(4))+underset(("body centred"))(1=4)`
Hence the resultant atachimetry is `A_(3) B_(4)`