Why do the early actinoids (like Uranium, Neptunium, and Plutonium) display a vastly wider range of — d and f Block Elements Chemistry Question

💡 Solution & Explanation

In lanthanoids, the $4f$ electrons are deeply buried. Conversely, in the early actinoids, the $5f, 6d$, and $7s$ energy levels possess nearly indistinguishable energies. This minuscule gap allows electrons from all three subshells to participate in covalent bonding.