Elements A and B combine to form the ionic compound A _x B _y . The anions of B are arranged in hcp array and the cations of A occupy all the octahedral voids. Determine the values of x and y.

Step-by-step solution

Let the number of anions B in the hcp array be N . The number of octahedral voids in a close-packed structure is equal to the number of packing atoms, which is N . Since cations A occupy all the octahedral voids, the number of cations A is also N . The ratio of the number of atoms of A to B is N : N = 1 : 1 . Therefore, the formula of the compound is AB , which gives x = 1 and y = 1 . Answer: x = 1 and y = 1