What is the group number of the -block element whose common divalent cation () in the series possess — d and f Block Elements Chemistry Question

💡 Solution & Explanation

The $d$ -orbital can hold a maximum of 5 unpaired electrons (a $d^5$ configuration). In the $3d$ series, the divalent cation with a $3d^5$ configuration is $Mn^{2+}$. Manganese ($Mn$, $Z=25$) has a neutral ground state configuration of $3d^5 4s^2$. In the modern periodic table, $Mn$ belongs to Group 7.