Ncert Exercises & Solutions

The most efficient packing is present in -

1. HCP and BCC

2. HCP and CCP

3. BCC and CCP

4. BCC and Simple cubic cell

HINT: HCP or CCP have highest packing efficiency.

Explanation:

Packing efficiency is the percentage of total filled space by particles and it can be calculated as:

= \frac{Volume occupied by four spheres in the unit cell}{Total volume of unit cell} \times 100

Since packing efficiency for HCP or CCP is calculated to be 74% which is the maximum among all types of crystals.