Question

De all changes involves interaction? By interaction do we mean only physical interaction? Find out examples of changes that affect each other non-physically.

Answer 1

Yes all changes involve interactions.
No, we cannot mean only physical interaction here. It may also be non-physical interactions. Let us give some examples having non-physical interactions.

• Conversion of water to vapour by evaporation: Here, water molecules attain kinetic energy due to the surrounding heat, thus they interact with each other and evaporate to vapour.
• Chemical reaction between iron and sulphur on heating: By heating, the atoms present in the mixture of iron and sulphur attains energy, interact with each other and form iron sulphide.