Which of following pairs is an example of isoelectronic species?
Which of following pairs is an example of isoelectronic species?
$\mathrm{O}^{--} ; \mathrm{Na}^{+}$
$\mathrm{O}^{--} ; \mathrm{F}$
$\mathrm{K} ; \mathrm{Ca}^{++}$
$\mathrm{Ar} ; \mathrm{Al}^{+3}$
Solution
Atoms and ions having the same number of electrons are isoelectronic species. $\mathrm{O}^{--}$and $\mathrm{Na}^{+}$ containing 10 electrons each are isoelectronic species.