In a face centred cubic lattice, atom `A` occupies the corner positions and atom `B` occupies the face centred positions. If one atom of `B` is missin from one of the face centred points,, the formula of the compound is `:`

Options

A. `A_2B`
B. `AB_2`
C. `A_2B_3`
D. `A_2B_5`

Answer

D

Explanation

`"No. of .A. atoms at corners "=8xx(1)/(8)=1`
`"No. of .B. atoms at face centres "=5xx(1)/(2)=(5)/(2)`
Forumal `=AB_(5//2) or A_(2)B_(5)`