Thank you for reporting, we will resolve it shortly
Q.
From the following pairs of ions which one is not an iso-electronic pair?
NEETNEET 2021Classification of Elements and Periodicity in Properties
Solution:
Isoelectronic refers to two atoms, ions, or molecules that have the same number of total electrons and the same number of valence electrons.
(a) $O ^{2-}$ and $F ^{-}$both have 10 electrons
(b) $Na ^{+}$and $Mg ^{2+}$ both have 10 electrons
(c) $Mn ^{2+}$ and $Fe ^{3+}$ both have 23 electrons
(d) $Fe ^{2+}$ has 24 electrons.
$Mn ^{2+}$ has 23 electrons.