Q. In $NaCl\$crystal each $Cl^{-}$ ion is surrounded by
A) $4\ Na^{+}$ ions
B) $6\ Na^{+}$ ions
C) $1\ Na^{+}$ ion
D) $2\ Na^{+}$ ions
Explanation
(b)
In $NaCl$ crystal, $Cl^{-}$ ions adopt cubic close packed arrangement and $Na^{+}$ ions occupy all the octahedral sites. Therefore, Na and Cl have 1 : 1 stoichiometry. In other words, each ${Na}^{+}$ ion is surrounded by six ${Cl}^{-}$ ions which are disposed towards the corners of a regular octahedron. Similarly, each ${Cl}^{-}$ ion is surrounded by six ${Na}^{+}$ ions.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.