Question

67. Packing factor of diamond cubic crystal structure is :
(A) 60%
(B) 56%
(C) 90%
(D) None of these
68. Madelung constant for the infinite line of ions of alternntir​

Answer 1

Answer: 90%

Explanation:

Answer 2

Answer:

The correct option is D. The packing fraction of the diamond cubic crystal is 34%.

Explanation:

• We are required to provide the packing fraction of the diamond structure.
• We are aware that the diamond has both a cubic and a hexagonal structure, but that the cubic structure is the more prevalent one.
• Whenever we discuss the cubic structure, we typically refer to it as having an fcc lattice as the unit cell dimension.
• Diamonds have a coordination number of four.
• However, there are eight atoms in its cubic structure—four from the fcc lattice and four alternately arranged in the tetrahedral gaps.
• FCC + atoms in tetrahedral voids equals the total amount of atoms.
• The total number of atoms is 8.
• r=√3 a/8
• Packing fraction = 32 πr^3/a^3
• Substituting the values, we get 0.34 as the packing fraction.

The correct option is D.

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