Among N^(-3), O^(-2) , Mg^(+2) and Al^(+3) (a) What is common in them. (b) Arrange them in the increasing ionic radii

Among N^(-3), O^(-2) , Mg^(+2) and Al^(+3) (a) What is common in them.

1.	Among N^(-3), O^(-2) , Mg^(+2) and Al^(+3) (a) What is common in them. (b) Arrange them in the increasing ionic radii
Answer» Answer :ISO electronic species `Al^(3+) lt MG^(2+) lt O^(2-) lt N^(3-)`