What are the key differences between the lanthanides and actinides?

Lanthanides primarily exhibit +3 oxidation states and have relatively less complex chemistry compared to actinides. Actinides can show a range of oxidation states (+3 to +6) due to the participation of 5f, 6d, and 7s electrons in bonding. Lanthanides are generally less radioactive, while actinides are highly radioactive with some being used in nuclear reactors and weapons. The actinides' 5f electrons are less shielded and more influenced by relativistic effects than the 4f electrons in lanthanides, leading to greater variability in their chemical behavior. Hope this helps.