|Class 10 Chemistry Chemical Reactions and Equations||Introduction|
Whenever lime is mixed with water we get a clear solution with and on touching the tube it feels hot. That is lime when mixed with water undergoes certain physical changes that makes it evolve heat and give a clear solution.
Similarly, the iron articles undergoes physical changes and develops a layer of rust on its surface. It reacts with the oxygen present in air and moisture and develops rust (hydrated iron (III) oxide).
These are all chemical reactions.