While lanthanoids predominantly exhibit a stable oxidation state, the early actinoids (such as ) exh — d and f Block Elements Chemistry Question

💡 Solution & Explanation

In the early actinoids, the energy differences between the $5f$, $6d$, and $7s$ orbitals are exceedingly small. Because these energy levels are nearly degenerate, all the electrons residing in these outermost subshells can be readily utilized for chemical bonding. This allows elements like Neptunium ($Np$) and Plutonium ($Pu$) to exhibit oxidation states up to $+7$.