Arrange the followingin orderof increasingradii ? (i) I, I^(+) , I^(-) (ii) C, N, Si, P (iii) O^(2), N^(3-) , S^(2-) ,F^(-)

Arrange the followingin orderof increasingradii ? (i) I, I^(+) , I^(-)

1.	Arrange the followingin orderof increasingradii ? (i) I, I^(+) , I^(-) (ii) C, N, Si, P (iii) O^(2), N^(3-) , S^(2-) ,F^(-)
Answer» Solution :(i) Sizeof a cation is always smallerwhile that of an ANION is always bigger than the neutral ATOM i.e., `I^(+) lt I lt I^(-)` (II) C andN lie in2ndperiodwhile Si and P liebelow them in the3rdperiod .Sinceelements in the 3th period havehigheratomicsizethanthosein the 2ndperiod therefore, atomicradii of Si and P arehigherthanthoseof C and N respectively .Sinceatomicradiidecrease fromleftto rightin a perioddut tohighernuclear charge therfore C hashigheratomicradius thanN andSi hashigheratomicradiusthan P. Thus the overall order of increasingatomic radii is : `N lt C lt P lt Si` (iii) Amongisoelectronic ionsthe SIZE ofanionsincrease as thenuclear chargedecreases. `F^(-) lt O^(2-) lt N^(3-).` SinceS belongto thirdperiodwhile `F, O, N` all belongto the secondperiodtherefore ionicradiusof `S^(2-) lt N^(3-) lt S^(2-)`