Chemistry - Mole Concept Question with Solution | TestHub

$1)$${\mathrm{O}}^{2-},{\mathrm{F}}^{-}$Both have$10$electrons
$2)$${\mathrm{Na}}^{+},{\mathrm{Mg}}^{+2}$Both have$10$electrons
$3)$${\mathrm{Mn}}^{2+},{\mathrm{Fe}}^{+3}$Both have$23$electrons
$4)$${\mathrm{Mn}}^{2+}$has$23$electrons while,${\mathrm{Fe}}^{+2}$have$24$electrons so, they are not an iso-electronic pair.