Question:
Which of the following statement is not true about the hexagonal close
packing?
(i) The coordination number is 12.
(ii) It has 74% packing efficiency.
(iii) Tetrahedral voids of the second layer are covered by the spheres of the
third layer.
(iv) In this arrangement spheres of the fourth layer are exactly aligned with
those of the first layer.
Solution:
Option (iv) In this arrangement spheres of the fourth layer are exactly aligned with
those of the first layer is the answer.