Question

please answer these objective type questions

Topic - Atomic And Ionic Radius

Class 11th

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Some of sort of explanation will be appreciated ;) ​

Answer 1

17. A

18. C

19. A

radius:

cation<parent atom < anion

Answer 2

-: Question 17 :-

The arrangement of the following species in increasing of their nuclear charge is :-

F^- < Na^+ < Mg^2+

Nuclear Charge = +9 < + 11 < + 12 .

And we knows that. ,The higher the size of atomic/ionic radii the lesser it has nuclear charge . So ,

Therefore, the arrangement of the following species in increasing their ionic radii is :-

Mg^2+ < Na^+ < F^-

Henceforth , ( A ) ✓

-: Question 19 :-

As we can see that , the nuclear charge of Hg^2+ > Hg^+ . So , Now we use the converse of the above .

The higher the nuclear charge the lesser it's Atomic / ionic radii .

So , The correct order of its ionic radii is :-

Hg^2+ < Hg^+ .

Henceforth , ( A ) ✓

-: Question 18 :-

Let us do this question with the periodic table which is in the attachment .It is clear from the periodic table that Iodine and bromine both are across the table ( left to right ) . So , The radii decreases .

And we knows that cation has always a lesser atomic radii then its neutral atom while anion has greater. So it is clear that the atomic radius is :-

I^+ < I < I^- .

Now we just have to find that is bromine smaller than I^- in atomic radius or not .

As bromine has a greater charge then I^- . So as the Concepts used above the size of radii will be :-

Br^- < I^-

Henceforth , ( C ) ✓