A cubic solid is made up iof two elements X and Y . Atoms Y are present at the corners of the cube and atoms X at the body centre. What is the formula of the compound ? What are the coordination number of X and Y ?

Explanation

As atoms Y are present at the 8 corners of the cube, therefore, number of atoms of Y in the unit cell = ` 1/8 xx 8=1`
As atoms X are present at the body cente, therefore , number of atoms of X in the unit cell =1
Ratio of atoms = X : Y =1 :1.
Hence, the formual of the compound is XY.
Coordinations number of each of X and Y =8