Question

What do you understand by isoelectronic species? Name the species that will be iso-electronic with each of the following atoms or ions.
(i) $F^{-}$
(ii) Ar
(iii) $Mg^{2+}$
(iv) $Rb^{+}$

Answer 1

"The isoelectronic species are those elements which have same or equal number of electrons or valence electrons

(i) ${ F }^{ - }$ is isoelectronic with ${ Mg }^{ 2+ }$ which has 10 electrons in its shell

(ii) Ar is isoelectronic with  $Cl }^{ - }{ S }^{ 2- }$ and ${ Ca }^{ 2+ }$which has 18 electrons in its shell

(iii) ${ Mg }^{ 2+ }$ is isoelectronic with Ne, ${ Al }^{ 3+ }$ and${ F }^{ - } F-$which has 10 electrons in its shell

(iv) ${ Rb }^{ + }$is isoelectronic with${ Br }^{ - }$which has 36 electrons in its shell"