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

Options

A. the coordination number is 12
B. it has 74 % packing efficiency
C. Tetrahedral voids of the second layer are covered by the sphere of the third layer
D. in this arrangment spheres of the fouth layer are exactly alingened with those of the first layer

Answer

D

Explanation

Hexagonal close packing can be arranging by two layers
A and B one another which can be diagramatically represented as ,

Here , we can see easily that 1st layer are not exactly aligned .
thus statement (d) is not correct while other statements (a) , (b) and (c ) are true .