Question

A compound which is cubic is formed by elements A and B. A atoms are at the corners and B atoms are at the face centres. What is the formula?

• A. $AB$
• B. $A{B}_2$
• C. $A{B}_3$
• D. $A_{3}B$

Answer 1

The correct option is C $A{B}_3$

A occupies each corner of the cube. So, the number of atoms of A is $8\times \frac{1}{8}=1$.

B occupies the centre of each face of the cube. So, the number of atoms of B is $6\times \frac{1}{2}=3$.

Hence, the formula is $A{B}_3$.