You assume that chemical activity in the brain cells is all that is required to generate our self awareness because there is nothing else which is physically detectable.
To a degree, although I think that phrasing is slightly pejorative. I don't 'assume', I deduce from the available evidence. We have a strong, growing vein of evidence that shows distinct correlations between brain function and our awareness - that, in and of itself, doesn't prove causation, of course, in either direction. Complicated experiments have demonstrated that the brain activity occurs in advance of the awareness, though, and the complete lack of any evidence for anything else means that it's a reasonable conclusion that brain activity is the source of awareness.
You can posit other things, but you need reasons to suggest them, and your personal incredulity about the prospect of awareness having purely physical sources isn't sufficient reason.
My problem with this is that I see nothing which defines chemical activity alone to be human awareness. The idea of emergent properties is just what it is - an idea in human imagination, but with no definition of how it works.
And 'I don't know' doesn't equal 'therefore souls'. If you want to posit souls you need to provide evidence for souls, and the lack of a complete theory of brain activity leading to awareness isn't it.
And there is the concept of free will. Chemical activity alone is not capable of generating free will choices, so I would have to assume that every choice I make has been pre determined by the chains of cause and effect which began with the big bang.
Right. That, again, is not an argument against the theory, that's just a description of the logical conclusion of it. You can dislike that conclusion, but again that's not a reason to discredit the theory, you have to provide some sort of reason to think that the reasoning is flawed. At the moment what you can't do is come up with a logical basis for free will, whether or not awareness is purely physical, because the very concept makes no senses - it can either be free or it can be will, but it can't be both at the same time.
O.