First of all, please edit your first sentence to complete the thought(s). (Arguably, you should form 2 sentences from it). Au exists as 196Au with atomic number 79. That means it has 118 neutrons, and 79 electrons and protons. BY DEFINITION, chemical reactions do not change sub-atomic particles, nor do they change the nucleus of any atom. So, the "reactions" aren't chemical, they're nuclear, and so are the "equations".
Many sources, including Wikipedia contain charts indicating which isotopes are stable. https://en.wikipedia.org/wiki/Isotope#/media/File:Isotopes_and_half-life.svg.
You should look at that, and pay special attention to the rows (Neutron number is on the vertical axis). The dark brown, almost black cells are stable. So, what you wish to do is by taking either a step up or a step right to move from one of the atoms (specific isotopes, actually) in air H,C,O,N,Ar,etc. 662
to move to (79,118). I'm not going to do that drudge work for you. You'll note that there are several rows between At. No. 19 and 79 that do not have a dark brown cell in them. That is, you can't get there from here without going through a radioactive element, even if you assume you can magically manipulate the atoms so that the one you 'tear a piece off of' remains, and the new isotope/element also doesn't spontaneously decay. However, it might be possible (again, I'm unwilling to do your work for you) to chose a path through an isotope which has very little high-energy radioactivity/radiation decay modes (Wikipedia has charts on the types of decay, and their energy, I believe. If not Wikipedia, then one of the (US) National Labs will have it.) So, in the cases where you have to "cross" a radioactive element (like Potassium, K) you should choose the route which has decay products which are most easily contained. The obvious question is why should that be a problem for a technology that can manipulate individual nucleons? It seems inconsistent to me that you can manipulate atoms and yet not be able to contain the radiation. 969