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. Derive the formula of the compound.

A compound formed by elements A and B has a cubic structure in which A

1.	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. Derive the formula of the compound.
Answer» Solution :As A atoms are PRESENT at the 8 CORNERS of the cube, therefore , number of atoms of A in the unit CELL `=1/8xx8=1` As B atoms are present in the face centres of the 6 FACES of the cube, therefore, number of atoms of B in the unit cell`=1/2xx6=3` `therefore` Ratio of atoms A:B =1:3 Hence, the formula of the compound is `AB_3`