A compound is formed by two elements X and Y. The atoms of element Y form a hcp structure. The atoms of element X occupy 1/3 of octahedral voids. What is the formula of a compound?

Step-by-step solution

Let the number of atoms of element Y in the hcp lattice be N . The number of octahedral voids in a close-packed structure is equal to the number of atoms in the lattice, which is N . Since atoms of element X occupy 1 3 of the octahedral voids, the number of atoms of X is N 3 . The ratio of the number of atoms of X to that of Y is N 3 : N = 1 : 3 . Therefore, the formula of the compound is XY ₃ . Answer: XY ₃