Consider a metal crystal with simple cubic, fce, and bce structures. Assume that the nearest neighbour atoms (spheres) touch each other in the unit cells. The correct statement is

• Correct answer
  A

  The percentage of the void space in different crystal structures follow the order: fcc < bcc < simple cubic.
• B

  The number of atoms in the unit cell are 14,9 and 8 for fcc, bcc and simple cubic structures, respectively.
• C

  The lowest percentage of the void space among the three crystal structures is approximately 48\%.
• D

  The percentage of the void space in any of the above crystal structures will depend on the lattice parameter and hence cannot be predicted without the knowledge of the lattice parameter.

Hence, the correct answer is option: 'A'.