Why does iron rust, but gold does not?
Quick Answer
Iron rusts because it readily reacts with oxygen and water to form iron oxides. Gold is much less reactive, so it resists corrosion in ordinary conditions.
The Full Story
Rust is not just surface dirt; it is a set of iron oxides and hydrated iron oxides that form when iron is exposed to oxygen and moisture. Iron oxidizes relatively easily because it is more chemically reactive than noble metals. Gold sits much lower on the reactivity scale, so air and water usually do not attack it. That is why gold jewelry keeps its shine while iron structures need coatings, paint, or alloying to slow corrosion.
Key Facts
YouTube Angle
Suggested video title for this topic:
"Why one metal turns reddish-brown and another stays shiny for centuries."
Was this answer helpful?
Tap a reaction — it helps us pick what to cover next.