Whichof the followingthe ratioof the sizesofcationof anionis smallest

1.	Whichof the followingthe ratioof the sizesofcationof anionis smallest ?
Answer» `NACI` `KCI` `MgC1_(2)` `CaF_(2)` Solution :Onmovingdown agroupionicradiusincreases . Thus`Na^(+)` has smallerradiusthan `K^(+)` and `Mg^(2+)` has smallerradiusthan `CA^(2+)`. Incontraston movingacrossa period , ionicradiusdecreases .Thus`Mg^(2+)` has smallerradiusthan`Ca^(2+)` .In other words `Mg^(2+)` has thesmallestradiusamongst `Na^(+) , K^(+) , Mg^(2+) ` and `Ca^(2+)` Amongst halogens `C1^(-)` has lergestradiusthan`F^(-)`. thus`MgC1_(2)` has thesmallestratioof the sizeof cationto anion.

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