Gold is the chemical element with 79 protons in each atomic nucleus. Every atom containing 79 protons is a gold atom, and all gold atoms behave the same chemically. In principle, we can therefore create gold by simply assembling 79 protons (and enough neutrons to make the nucleus stable). Or even better, we can remove one proton from mercury (which has 80) or add one proton to platinum (which has 78) in order to make gold. The process is simple in principle but hard to do in practice. Adding or removing protons from a nucleus are types of nuclear reactions. As such, no series of chemical reactions can ever create gold. Chemical reactions change the number and shape of the electrons in an atom but leave the nucleus of the atom unchanged. The ancient alchemist dream of creating gold by simply reacting chemicals is therefore impossible. You have to use nuclear reactions to create gold. The difficulty is that nuclear reactions require a lot of energy.