Question

$bcc$ and $hcp$ has same packing efficiency. Both have same number of atoms per unit cell and same arrangement.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (D)

If both assertion and reason are false

Answer 2

BCC has 68% and HCP has 74% packing efficiency. BCC - 2 atoms per unit cell, HCP - 4 atoms per unit cell In BCC, particles are present at corners and one particle is present at the centre within the body of the unit cell. In HCP, the packing gives a hexagonal pattern.