First slide

Crystal lattices and unit cells

Question

The NaCl lattice has the cubic unit cell as shown.The correct statements are
.

Moderate

A

r_cation+r_anion= a/2
B

Cl^-- at faces and edges
C

Na⁺at corners and body center
D

radius of cation to anion is $\sqrt{2} - 1$

Solution

Since, side $r_{+} + r_{-}$
and diagonal = $2 r_{-} = \sqrt{2} (r_{+} + r_{-})$
$∴ 2 r_{-} = \sqrt{2} (r_{+} + r_{-})$
$\sqrt{2} = \frac{r_{+} + r_{-}}{r_{-}} = \frac{r_{+}}{r_{-}} + 1$
$∴ \frac{r_{+}}{r_{-}} = \sqrt{2} - 1 = 0.414$

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