Question

$r_{N{a}^{+}}=195pm$ and $r_{C{l}^{-}}=281pm$ in $NaCl$ (rock salt) structure. What is the shortest distance between $N{a}^{+}$ ions?

• A. $778.3pm$
• B. $673.06pm$
• C. $195.7pm$
• D. $390.3pm$

Answer 1

Answer: (B)

The shortest distance between two $N{a}^{+}$ion $=\frac{1}{2}$ face - diagonal
$=\frac{1}{2}\times \sqrt{2}2r_{Na}++r_{Cr}$
$=\sqrt{2}(195+281)pm=673.06pm$