Q. If the distance between $Na^{+}$ and $Cl^{-}$ ions in sodium chloride crystal is X pm, the length of the edge of the unit cell is
A) 4 X pm
B) X/4 pm
C) X/2 pm
D) 2 X pm
Explanation
(d)
In $NaCl,\$the length of the edge of the unit cell is
$= 2 \times \$distance between $Na^{+}$ and $Cl^{-}$ ions hence, $a = 2X\ pm.$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.