First slide

Crystal lattices and unit cells

Question

The CORRECT statement(s) for cubic close packed (ccp) three dimensional structure is (are)

Difficult

A

The number of the nearest neighbours of an atom present in the topmost layers is 12
B

The efficiency of atom packing is 74%
C

The number of octahedral and tetrahedral voids per atom are 1 and 2, respectively
D

The unit cell edge length is $2 \sqrt{2}$ times the radius of the atom

Solution

Packing fraction $= \frac{V o l . o f a t o m}{V o l . o f u n i t c e l l} \times 100$
$= \frac{4 \times \frac{4}{3} π r^{3}}{a^{3}} \times 100$
$= \frac{4 \times \frac{4}{3} π r^{3}}{{(2 \sqrt{2} r)}^{3}} \times 100$
=74%
Total no.of octahedral and tetrahedral voids 4 and 8 respectively.

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App