Problem: The density of solid Cu is 8.96 g/cm3. How many atoms are present per cubic centimeter of Cu? If a solid, Cu adopts a face-centered cubic unit cell. How many unit cells are present per cubic centimeter of Cu? What is the volume of a unit cell of this metal? What is the edge length of a unit cell of Cu?

FREE Expert Solution

Face-centered cubic lattice contains an atom in each of the face of the cube and an atom in each of the corners:



a) Cu atoms per cm3


8.96  g cm3×1 mol Cu63.55 g Cu×6.022 × 1023 Cu atoms1 mol Cu

= 8.49 x 1022 Cu atoms/cm3


There are 8.49 x 1022 Cu atoms per cubic centimeter of Cu


b) Unit cells per 1 cmCu


Cu atoms per unit cell:

  • corner atoms = 1/8  → 8 corners
  • face atoms = 1/2 → 6 faces 


atomsunit cell = 8(18)+ 6(12) = 4 Cu atoms/ unit cell

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Problem Details

The density of solid Cu is 8.96 g/cm3. How many atoms are present per cubic centimeter of Cu? 

If a solid, Cu adopts a face-centered cubic unit cell. How many unit cells are present per cubic centimeter of Cu? 

What is the volume of a unit cell of this metal? 

What is the edge length of a unit cell of Cu?