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 centred. One of the A atom is missing from one corner in unit cell. The simplest formula of compound is :

Options

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

Answer

C

Explanation

A-corners = 8, one atom is missing so `8 - 1 = 7,` Contribution of corner `=7xx(1)/(8)=(7)/(8)`
B-Face centre `= 6`, Contribution `=6xx(1)/(2)=3"   "therefore A(7)/(8)B_(3)"   "A_(7)B_(24)`.