Ncert Exercises & Solutions

Match the type of packing given in Column I with the items given in Column II.

Column I	Column II
A. Square close packing in two dimensions	1. Triangular voids
B. Hexagonal close packing in two dimensions	2. Pattern of spheres is repeated in every fourth layer
C. Hexagonal close packing in three dimensions	3. Coordination number = 4
D. Cubic close packing in three dimensions	4. Pattern of sphere is repeated in alternate layers

Codes

Hint: Square close packing in two dimensions has coordination number 4.

A. Square close packing in two dimensions each sphere have coordination number 4, as shown below

B. Hexagonal close packing in two dimensions each sphere have coordination number 6 as shown below and creates a triangular void

C. Hexagonal close packing in 3 dimensions is a repeated pattern of sphere in alternate layers also known as ABAB pattern

D. Cubic close packing in a 3 dimensions is a repeating pattern of sphere in every fourth layer