Discussion Forum



1)

Identify the correct order of ionic radii of the following ions.


A) $Al^{3+} > K^{+} > Mg^{2+}> Li^{+}$

B) $K^{+} >Mg^{2+} > Al^{3+} > Li^{+}$

C) $K^{+} > Li^{+} >Mg^{2+}>Al^{3+}$

D) $K^{+} > Mg ^{2+} >Li^{+} > Al^{3+}$

Answer:

Option C

Explanation:

Ionic radii of alkali metal ion is larger than alkaline earth metals due to higher nuclear charge.On the other hand, on moving down the group ionic radii increases. Thus, correct order of ionic radii is 

$K^{+} > Li^{+} >Mg^{2+}>Al^{3+}$