Wouldn't a big enough asteroid have an inner part which survives entry? You seem to be saying that it's impossible for any meteorite that might have these chemicals to not be completely vaporized which seems doubtful. Have you got a source?
So you survived re-entry. Now, you get to survive impact. Seems like the energy released would also be damaging
So you survived re-entry. Now, you get to survive impact. Seems like the energy released would also be damaging