JEE Advanced levelSingle correct optionDifficulty 3 of 3ss158
A cubic unit cell has atoms Z at six corners and atoms W at the two remaining corners (adjacent along one edge). Atoms X are at the centres of all six faces. The formula of the compound is
AZX6WXX3
BZWXX3
CZX3WXX12
DZX3WX2XX12
Answer: C
Z=6×81=43; W=2×81=41; X=6×21=3. The ratio 43:41:3=3:1:12, hence ZX3WXX12.