Hi,
I hope I'm not on the wrong forum, but I have a question regarding the actinides and their oxidation states. The early actinides possess a wide range of oxidation states, diverging from the lanthanides, which is explained by relativistic electron effects. Namely the f- and d-orbitals are more (chemically) available for the early actinides and thus have a wide range of oxidation states. Now that's clear, but what I don't get is why the late actinides then resemble the lanthanides? The relativistic effect still holds for these elements, so why are they suddenly reduced to the dominant +3 ox. state? Is it because the 5f-orbitals lower in energy after 95Am, and, if so, why is that so? I hope someone has an answer!
Greetings,
Mitchel