Are non carbon based life forms possible? Why or why not? Give at least two reasons to support your answer

     The idea of non carbon based life forms are unlikely but I believe it could be possible on another planet or if a species evolves to a point where it actually changes its chemical structure. I have heard of silicon based life, fluorine based life, and electromagnetic based life forms. I do believe it is possible that an element will be found to replace carbon one day and then life will no longer require it. 
     One example of an electromagnetic life form is plasma bodies. Ninety percent of the universe consists of dark matters. In the dark universe plasma bodies flourish. These extraterrestrial life forms possess bio-plasma bodies. These are electromagnetic bodies, which generate electromagnetic fields and radiate electromagnetic waves.
     The second example is silicon life forms, this is likely because silicon is probably one of the more likely replacements for carbon. Most likely, humans would not be able to became silicon based but maybe in a different galaxy, extraterrestrial life has silicon based creatures.