what are points we should take care while determining the increasing order in size of ions .. like for eg k+,sr2+,ar .... like we can determine increasing order of iso electronics from nuclear charge so is there any another way to determine increasing size of "different" ions.... no links

Dear Student
Your I part of question is not clear? What are points? Which point. You please mention it clearly. I will solve it. 
When isoelectronic species are considered more the positive charge less will be the size of the ion. This is because more the positive charge, more will be the attraction between the nucleus and the outer electrons and they are attracted more towards the nucleus. So less will be the size. Among the given  ions  Ar > K+ > Sr2+. Similarly more the negative charge more will be the size of the ion. For ex., S2- > Cl- > Ar

​There is no other way to find the size of the ion. 

Regards
Geetha L
 

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