If three elements P, Q and R crystallize in a cubic solid lattice with P atoms at the corners, Q atoms at the cube centre and R atoms at the centre of the faces of the cube, then write the formula of the compound.

If three elements P, Q and R crystallize in a cubic solid lattice with

1.	If three elements P, Q and R crystallize in a cubic solid lattice with P atoms at the corners, Q atoms at the cube centre and R atoms at the centre of the faces of the cube, then write the formula of the compound.
Answer» Solution :Atoms P PER unit cell = 8 x 1/8=1, Atoms Q per unit cell =1, Atoms R per unit cell = 6 x 1/2=3 Hence, the formula is `PQR_3`