• # question_answer 69) A compound formed by elements A and B has a cubic structure in which A atoms are at the corners of the cube and B atoms are at the face centres. The formula for the compound is A)  ${{A}_{2}}{{B}_{3}}$                 B)  $A{{B}_{3}}$C)  ${{A}_{3}}B$                     D)  ${{A}_{3}}{{B}_{2}}$

Number of corner atom $(A)=8\times \frac{1}{8}=1$ Number of face centre atom $(B)=6\times \frac{1}{2}=3$ Hence, formula of the compound is $A{{B}_{3}}$.