1

### AIPMT 2000

In cube of any crystal A-atom placed at every corners and B-atom placed at every centre of face. The formula of compound is
A
AB
B
AB3
C
A2B2
D
A2B3

## Explanation

A atoms are at 8 corners of the cube

$\therefore$ No. of A atoms per unit cell = 8 $\times$ ${1 \over 8}$ = 1

B atoms are at the face centre of six faces.

$\therefore$ No. of B atoms per unit cell = 6 $\times$ ${1 \over 2}$ = 3

Thus, formula of compound = AB3