Question

Q.9 Arrange the following isoelectronic species in the order of their increasing radii
Na, Mg?, sr". Al
not it
found to exist in nature hl N is not diamagnetic substanc​

Answer 1

Answer:

Answer

O

2−

,F

−

,Na

+

,Mg

2+

have the same number of electrons (10). Their radii would be different because of their different nuclear charges. The cation with the greater positive charge will have a smaller radius because of the greater attraction of the electrons to the nucleus. Anion with the greater negative charge will have the larger radius. In this case, the net repulsion of the electrons will outweigh the nuclear charge and the ion will expand in size. The order of IE will be opposite to that of ionic radii as smaller the size, the control of nucleus on outermost electron will be more and hence more energy will be required to remove an electron. Hence the correct order is O

2−

<F

−

<Na

+

<Mg

2+