mg2+ ion is smaller than o2- ion although they have the same electronic structure.EXPLAIN??

Asked by mani.karmanya | 13th Aug, 2016, 10:40: AM

Expert Answer:

Oxygen and magnesium are isoelectronic species i.e.  they have same number of electrons but differ in the magnitude of their nuclear charge.

Mg+2 ion has 12 protons in its nucleus and therefore exert higher effective nuclear charge compared to O2- which has 8 protons.

As a result, the inner shells and the valence shell electrons are more strongly attracted by the nucleus in Mg+2.

Therefore Mg+2 ion is smaller in size than O2- ion although both have same electronic structure. 

Answered by Vaibhav Chavan | 13th Aug, 2016, 04:29: PM