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_2B`
C. `A_4B_3`
D. `A_3B_4`

Answer

D

Explanation

There were 6 A atoms on the face centres. Removing face-centred atoms one of the axes means removal of 2A atoms.

Now, no of A atoms per unit cell
`{:(=8xx1/8,4xx1/2,=3),("(Corners)","(face-centred)",):}`
No. of B atoms per unit cell
`{:(=12xx1/4,1,=4),("(edge centred)","(body-centred)",):}`
Hence, the resultant stoichoimetry is `A_3B_4`