How many of the following cations possess a pseudo-inert gas electronic configuration ( in the outer — Chemical Bonding Chemistry Question

💡 Solution & Explanation

A pseudo-inert gas configuration has 18 electrons ($ns^2 np^6 nd^{10}$) in the outermost shell. These are characteristic of transition/post-transition metals like $Cu^+$, $Ag^+$, $Zn^{2+}$, and $Cd^{2+}$. The remaining ions ($Na^+, K^+, Mg^{2+}, Ca^{2+}$) belong to the s-block and have 8-electron inert gas configurations.