which of the following statemets is not true about the hexagonal close packing ?

Options

A. The coordination number is 12.
B. It has 743 packing efficiency
C. Tetrahedral voids of the second layer are covered by the spheres of the third layer.
D. In this arrangement spheres of the fourth layer are exactly aligned with those of the first layer.

Answer

D

Explanation

Hexagonal dose packing (hep) can be arranged by two layers A and B one over another which can be diagrammatically represented as:
In the above figure the first layer and fourth are not exactly aligned. Thus, statement (D) is not correct while other statements, i.e., (A), (B) and (C) are true.