Pretty hefty assumptions here.
(1) Sol contains elements other than hydrogen and helium? Has anyone taken a sample from the sun and tested it out? Blowing hot air much these days?
(2) You assume these elements didn't form in the big bang.
(3) You assume there was a big bang.
(4) Sol is not a first generation star, which goes back to the circular argument.
(5) Sol has metalic elements. Again, anyone ever taken a sample from the sun? Seems to me like the scientific community is just blowing hot air on this one LOL
1) One word - spectroscopy, however there are other methods, see
Error 404 - non-existent address, high school science really.
2) The EVIDENCE for the big bang suggests these elements didn't form in the big bang.
http://www.umich.edu/~gs265/bigbang.htm. There are links to other articles at the bottom, and quite a good finishing paragraph.
3) See 2
4) The EVIDENCE from 2, and the EVIDENCE from 1, along with what we know about supernova etc. would suggest that Sol is not a first generation star.
5) see 1
If you are looking for 100% proof, never going to happen, as I am sure has been pointed out on these forums there is no such thing as 100% proof. However the EVIDENCE leads us to... is not the same as assumptions.