Match the following columns.

(A). A atoms are at the corners and face centers, so number of A atoms =8×18+12×6=1+3=4                                                                                                       corner atoms       Face center atoms    B atoms are at the edge centers and body center, so number of B atoms per unit cell =12×14+1=3+1=4     Ratio of A and B = 4 : 4 = 1:1 so formula is AB.(B).A atoms are at the corners, so number of A atoms per unit cell =8×18=1 atom.    B atoms are at the body diagonals, so number of B atoms per unit cell = 4 x 1 = 4.   ∴ Formula of molecule = AB4.(C). When A atoms are at the corners and B atoms are at face centers, the formula is AB3.