Question

The empty space left in hcp in three dimensions is :

• A. $26\%$
• B. $74\%$
• C. $52.4\%$
• D. $80\%$

Answer 1

The correct option is A $26\%$

Packing efficiency is the ratio of the volume occupied by spheres in unit cell to the volume of hcp unit cell multiplied by 100.

For hcp unit cell, packing efficiency (or volume occupied) is 74%.

The empty space left in hcp in three dimensions is $100-74=26$%.