Question

Copper crystallises in a structure of face centerd cubic unit cell. The atomic radius of copper is 1.28 Å. What is axial length on an edge of copper.

• A. 2.16 Å
• B. 3.62 Å
• C. 3.94 Å
• D. 4.15 Å

Answer 1

Answer: (B)

3.62 Å

Answer 2

4r =$a\sqrt{2}$

$a = \frac{4r}{\sqrt{2}} = \frac{4 \times 1.28}{\sqrt{2}}$Å = 3.62 Å