Q. Copper crystallises in fcc lattice with a unit cell edge of 361 pm. The radius of copper atom is
A) 181 pm
B) 108 pm
C) 128 pm
D) 157 pm
Explanation
(c)
Copper crystallises in fcc lattice.
If, $r$ = radius
$\ \ \ \ a =$ edge length
Then $r = \frac{a}{2\sqrt{2}} = \frac{361}{2\sqrt{2}}\ pm$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ = 127.633\ pm\ \approx 128\ pm$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.