That's not alchemy. Alchemy was changing elements, specifically not-gold metals into gold, not just molecules.
You can turn copper + zinc into brass, but the atoms of copper and zinc still exist within brass. You can't turn a copper atom into a zinc atom.
You can mix gold atoms with something else to make a gold alloy, you can't change gold atoms into something else or vice versa.
Do you know the difference between an atom and a molecule? I can't tell if you're just trolling at this point.