Question

The set representing the correct order of ionic radius is

• A. $Li^{+} > Be^{2+} > Na^{+} > Mg^{2+}$
• B. $ Na^{+} >Li^{+} > Mg^{2+}> Be^{2+}$
• C. $Li^{+} > Na^{+} > Mg^{2+}> Be^{2+}$
• D. $Mg^{2+}> Be^{2+} >Li^{+} > Na^{+} $

Answer 1

Answer: (B)

In general, the ionic radius increases on moving from top to bottom in group and decreases on Inoving from left to right in period So, the correct order is

$\underset{0.98\, \mathring{A}}{Na^{+}} >\, \underset{0.68\, \mathring{A}}{Li^{+}}>\, \underset{0.65\, \mathring{A}}{Mg^{2+}}>\,\underset{0.62\, \mathring{A}}{Be^{2+}}$