Question

So, rusting of iron is a chemical change or physical change???

Answer 1

The rusting of iron is a chemical change because it is two substances reacting together to make a new substance. When iron rusts, iron molecules react with oxygen molecules to make a compound called iron oxide. Rusting would only be a physical change if iron molecules remained pure iron throughout the process. The rusting of iron is an illustration of the principle of corrosion. Corrosion is a chemical change that usually occurs in metals that come into contact with an electrolyte. Water is the electrolyte that most commonly enables oxygen and iron to combine. This is why iron rusts when exposed to both water and air.