we know metals are made of Atoms, rather than the 5 elements. However, if it were just atoms, metal transmutation should be possible, if we strip down a piece of metal into its constituents, right?
Almost. Except, atoms have something called a ‘nucleus’, which is fundamentally different for different elements. A nucleus basically is a set of neutrons (which have no charge) and protons (which are positively charged). Different elements have different number of protons, though they might have the same number of neutrons.
So can we add or remove protons from base metals, and transmute them to gold?