Which of the following statement is correct for a closet packed structure? (i) Each tetrahedral void is surrounded by 4 spheres and each sphere is surrounded by 8 tetrahedral voids.
(ii) Each octahedral voids is surrounded by 6 spherus and each sphere is surrounded by 6 octahedral voids.
(iii) The number of tetrahedral voids in a closest-packed arrangement is twice the number of spheres.
(iv) The number of octahedral voids in a closest-packed arrangement is equal to the number of spheres.

Options

A. (i), (ii)
B. (iii), (iv)
C. (i), (iii)
D. (i), (ii), (iii), (iv)

Answer

4

Explanation

Tetrahedral voids are surrounded `4` spheres sitting at the corners of a regular tetrahedron and are present in `HCP`as well as `C CP`.
for every sphere in the closest packed arrangement there is one octahedral void and two tetrahedral voids. The octahedral voids are larger than the tetradral voids.