Question

The hcp and ccp structure for a given element would be expected to have_______.

• A. same coordination number
• B. same density if made up of same element
• C. same packing fraction
• D. same number of atoms in single unit cell

Answer 1

Answer: (A), (B), (C)

same coordination number
same density if made up of same element
same packing fraction

The HCP and CCP structure for a given element would be expected to have:

(A) same coordination number of 12.

(B) same density if made up of the same element as mass and volume occupied and volume available for each atom is same.

(C) same packing fraction. In both unit cells, 74% of total volume is occupied.

(D) Different number of atoms in single unit cell

• ccp has 4 atoms per unit cell
  
• hcp has 6 atoms per unit cell