In a face centred cubic arrangement of A and B atoms whose A atoms are at the corner of the unit cell and B atoms at the face centres. Once of the A atom is missing from one corner in unit cell. The simplest formula of compound is

Options

A. `A_(1)B_(3)`
B. `AB_(3)`
C. `A_(7)B_(24)`
D. `A_(8)B_(21)`

Answer

3

Explanation

Effective no. of 'A' atoms `=7xx(1)/(8)=(7)/(8)`
effective no. of 'B' atoms `=6xx(1)/(2)=3`
formula `=A_(7//8)B_(3)=A_(7)B_(24)`