Question:
Which of the following is not true about the voids formed in 3-dimensional
hexagonal close-packed structure?
(i) A tetrahedral void is formed when a sphere of the second layer is present
above triangular void in the first layer.
(ii) All the triangular voids are not covered by the spheres of the second
layer.
(iii) Tetrahedral voids are formed when the triangular voids in the second
layer lie above the triangular voids in the first layer and the triangular
shapes of these voids do not overlap.
(iv) Octahedral voids are formed when the triangular voids in the second
layer exactly overlap with similar voids in the first layer
Solution:
Option (iii) and (iv) are the answers.