Question

A three element pqr in a cubic solid with p atoms at corners and q atoms at centre and r atom are at edges write formula of compound

Answer 1

If p atoms are at the corners, q atoms at the cubic center and r atoms at the faces of the cube then the formula of the compound can be derived as follows:

Atom p is shared by 8 corners

Atom q is present at the centre

1 atom of r is shared by 4 unit cells

Effective number of atoms of p per unit cell = 8 * 1/8 = 1

Effective number of atoms of q per unit cell = 1

Effective number of atoms of r per unit cell = 12/4 = 3

Hence formula of the compound is pqr3