According to NCERT (Section 4.6.3), actinoids exhibit a greater range of oxidation states (e.g., +3, +4, +5, +6, +7) compared to lanthanoids (which are predominantly +3). This is attributed to the fact that the 5f, 6d, and 7s energy levels are of comparable energies in actinoids. This implies that the energy difference between 5f and 6d orbitals is small (lesser), allowing electrons from both subshells to participate in bonding. In contrast, in lanthanoids, the 4f orbitals are relatively buried and have a larger energy gap with the 5d orbitals, restricting the number of oxidation states available.