Question

Arrange the following sets of ions in order of decreasing ionic radii.

(a) , , , 

 

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(b) , , 

 

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Answer 1

Among isoelectronic species, radius of cation decreases with increase in no . of positive charge.

So, the correct order of ionic radii will be:

$He^+ >Li^{2+} >Be^{3+}$