Which is not true about the voids formed in three dimensional hexagonal close-packed structure-

Options

A. A tetrahedral voids is formed when a sphere of the second layer is present above triangular voids in the first layer
B. All the triangular voids are not covered by the spheres of the second layer
C. Tetrahedral voids are formed when the treangular voids in the second layer lie above the triangular voids in the first layer and the triangular shapes of these voids do not overlap.
D. Octahedral voids are formed when the triangular voids in the second layer exactly overlap with similar voids in the first layer.

Answer

C, D

Explanation

c,d are not true.
c is not true because octahedral and not tetrahedral voids are formed in doing so.
d is not true because octahedral void is formed by the combination of two triangular voids one with vertex upwards and the other with vertix dounward and not by thier overlap as suggested.