One of the best-designed features in nature is what you have here. There is no rust on gold. It is not corroding. It mocks oxygen. The reason is absolutely pure chemistry.
Like a king, gold finds its place in the periodic table. Its electron arrangement qualifies it as noble, unreactive. The outer shell of electrons is stable and full. It doesn't want to share. Doesn't need to bond.
Iron gives up electrons readily, thus it rusts. It combines with oxygen like a drunk man searching for a fight. Still, gold keeps its electrons close.
Gold's nucleus and electrons attract more strongly than in most metals. Our term for this is electronegativity. Gold's is high. Iron's isn't.
The electron layout of gold finishes in 5d¹⁰6s¹. That corresponds exactly with a full d-orbital. Consistent. Finish. Iron ends in 3d⁶4s². That's unstable. Ready to react.
For the metal, the difference is life and death.
For a thousand years, gold can lie at the bottom of the sea. It arises brilliant. That same iron piece would break down into red dust.
This stability made gold precious. People of ancient times discovered it. Maintained it. Traded it. They didn't know about electron configurations. They knew, though, that gold lasted.
