Physical changes VS. chemical changes

Difference

  • 1 Explanation In a physical change, the molecules are rearranged while their actual composition remains same. In a chemical change, the molecular composition of a substance completely changes and a new substance is formed.
  • 2 Example Some example of physical change are freezing of water, melting of wax, boiling of water, etc. A few examples of chemical change are digestion of food, burning of coal, rusting, etc.
  • 3 Reversibility Physical change is easily reversible i.e original substance can be recovered. Chemical change is irreversible i.e. original substance cannot be recovered.
  • 4 Formation of new substance In physical change, no new substance is formed. A chemical change is always accompanied by one or more new substance(s).
  • 5 Type of Change Physical change is a temporary change. Chemical change is a permanent change.
  • 6 Energy Production In a physical change, no energy is produced. In a chemical change, energy is produced (heat, light, sound, etc.)
  • 7 Absorption of Energy Physical change involves very little to no absorption of energy. During chemical reaction, absorption and evolution of energy takes place.
  • 8 Affects Physical change affects only physical properties i.e. shape, size, etc. Chemical change both physical and chemical properties of the substance including its composition.