Question

Copper crystallises infcc lattice with a unit cell edge of 361 pm. The radius of copper atom is:

• A. 108 pm
• B. 128 pm
• C. 157 pm
• D. 181 pm

Answer 1

Answer: (B)

128 pm

Answer 2

FCC lattice

a = 361 pm

$a\sqrt{2}$ = 4r

r = $\frac{361 \times \sqrt{2}}{4}$ = 127.6 » 128 pm.