In a multi layered close-packed structures.

In a closed packed structure

How are spheres arranged in first layer of cubic close-packed structures? How are successive layers of spheres placed above this layers?

The number of packed particles in a cubic close-packed structure is x. If the number of tetrahedral and octahedral holes in this structure are y and z, then-

Coordination number in a square close packed structure and hexagonal close packed structure respectively are

The two types of holes which occur in any close-packed structures are

Why a hexagonal close-packed structure and a cubic close-packed structure for a given element would be expected to have the same density?

Why a hexagonal close-packed structure and a cubic close-packed structure for a given element would be expected to have the same density?

Why a hexagonal close-packed structure and a cubic close-packed structure for a given element would be expected to have the same density?