Question

A solid metal has ccp or fcc structure. The relation of side of cube $\left(a\right)$ and radius of atom $\left(r\right)$ will be:

• A. $a=2r$
• B. $a=2\sqrt{2}r$
• C. $a=\frac{4}{\sqrt{3}}r$
• D. $a=\sqrt{3/2}r$

Answer 1

The correct option is B $a=2\sqrt{2}r$

In case of ccp or fcc structure:

$4r=\sqrt{2}a\Rightarrow a=\frac{4r}{\sqrt{2}}$

$\therefore a=2\sqrt{2}r$

Hence, the correct answer is option $\text{B}$.