Is Tarnishing a Chemical Change?
Answer – Yes, tarnishing is a chemical change.
Explanation:
Chemical changes are those caused when substances react with one another to produce new substances.
Tarnishing occurs to metals or objects made of metals when they are exposed (usually for long periods of time) to air, water or other certain other elements. When a metal tarnishes, it means that an oxidation reaction has taken place: the exposure has caused the metal to oxidize.
The oxides then form a layer over the metal, altering its appearance. This coating can be removed by scrubbing it off, or by exposing it to other compounds/elements that can reverse the oxidation (i.e. prompting the oxide to undergo a reduction reaction).
When iron or objects made of iron tarnish, the process is commonly called rusting.
