A solid PQ have rock salt type structure in which Q atoms are at the corners of the unit cell. If the body centred atoms in all the units cells are missing, the resulting stoichiometry will be
(C) In rock salt structure, atoms at the corner are also present at the face centres and hence
ZQ=8 x 1/8 + 6 x 1/2 =4
And, the atoms at body centre also present at edge centres. But from question, body centres are missing and hence
ZP = 12 x 1/4 = 3
Formula of resulting solid - P3Q4.