2D and 3D closed packing

the coordination no. in 3D close packing of spheres having packing of the type (ABC) (ABC) is Y. calculate the value of Y/2

Packing refers to the arrangement of constituent units in such a way that the forces of attraction among the constituent particles is the maximum and the contituents occupy the maximum available space. In two dimensions, there are hexagonal close packing and cubic close packing. In three dimentions, there are hexagonal, cubic as well as body centred close packings. The empty space left in hcp packing is:

The difference in coordination numbers of hexagonal close packing in 3D and square close packing in 2-D, of identical spheres is:

Find out the ratio of maximum number of triangular voids and rectangular voids formed by nine atoms according to HCP and square close packing in 2D respectively

Three-dimensional close packing in solids is referred to as stacking the second square closed packing exactly above the first. In this tight packing, the spheres are horizontally and vertically correctly balanced. Similarly, we can obtain a simple cubic lattice by adding more layers, one above the other. This can be done in two ways. Three-dimensional close packing from two-dimensional square close-packed layers: By putting the second square closed packing exactly above the first, it is possible to form three-dimensional close packing. In this tight packing, the spheres are horizontally and vertically correctly balanced. Similarly, we can obtain a simple cubic lattice by adding more layers, one above the other.Three-dimensional close packing from two-dimensional hexagonal close-packed layers: With the assistance, of two-dimensional hexagonal packed layers, three-dimensional close packing can be obtained. The coordination number of cubic closed packing is:

Three-dimensional close packing in solids is referred to as stacking the second square closed packing exactly above the first. In this tight packing, the spheres are horizontally and vertically correctly balanced. Similarly, we can obtain a simple cubic lattice by adding more layers, one above the other. This can be done in two ways. Three-dimensional close packing from two-dimensional square close-packed layers: By putting the second square closed packing exactly above the first, it is possible to form three-dimensional close packing. In this tight packing, the spheres are horizontally and vertically correctly balanced. Similarly, we can obtain a simple cubic lattice by adding more layers, one above the other.Three-dimensional close packing from two-dimensional hexagonal close-packed layers: With the assistance, of two-dimensional hexagonal packed layers, three-dimensional close packing can be obtained. The correct statement about zns crystal is:

Calculate the value of (Z)/(10). Where z = co-ordination number of 2D-square close packing + Co-ordination number of 2D-hcp + Co-ordination number of 3D-square close packing + Co-ordination number of 3D, ABCABC........packing + Co-ordiantional number of 3D, ABAB.......packing .

In a square close packing pattern, one atom is in contact with how many atom in the 2D plane base ?