rReactions/Structure of Cerium
Electron Shell Configuration=(Xe)4f15d16s2

http://www.webelements.com/webelements/elements/media/kossel-pics/Ce.jpg
Cerium has a very unique reaction tendency. Because it has ionic forms all the way to an 8+ ion it can react with almost any element on this earth. However the most common reactants of cerium are oxide, chloride, and sulfide. Cerium must lose only two outer electrons to become stable so other 2- anions tend to be a very popular in cerium reactions. Because cerium reacts with so many elements it is near impossible to find pure cerium metal in the atmosphere. Therefore, cerium must be obtained by single replacement reactions and dissociation reactions.
The two most common reactions to obtain cerium are:
2Ca(s) + 2CeF3(aq) → 2Ce(s) + 3CaF2(aq)
Another way to produce pure Cerium is;
3Li(s) + CeCl3(aq) → Ce(aq) + 3LiCl