What is the distinguishing layer between hexagonal close packing and cubic close packing?

Q. What is the distinguishing layer between hexagonal close packing and cubic close packing?

Q. Stacking of a second layer of sphere over the first layer of 2-D hexagonal close packing will result in formation of:

Q.

Which of the following statement is not true about the hexagonal close packing ?

(a) The coordination number is 12

(b) It has 74% 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

Q. Match the types of packing given in column I with the items given in column II.

	Column I		Column II
(i)	Square close packing in two dimension	(p)	Triangular voids
(ii)	Hexagonal close packing in two dimensions	(q)	Pattern of spheres is repeated in every fourth layer
(iii)	Hexagonal close packing in three dimension	(r)	Coordination number=4
(iv)	Cubic close packing in three dimension	(s)	Pattern of spheres is repeated in alternate layers

Q. ABABAB layering pattern is called hexagonal close packing, found in HCP lattice.
If true enter 1,else enter 0.