Question

How can you distinguish between a physical change and a chemical change?

Answer 1

Answer:

Physical Change

• When a substance undergoes a physical change, its composition remains the same despite its molecules being rearranged.
• Physical change is a temporary change.
• A Physical change affects only physical properties i.e. shape, size, etc.
• A physical change involves very little to no absorption of energy.
• Some examples of physical change are freezing of water, melting of wax, boiling of water, etc. .
• In a physical change, no new substance is formed.
• Physical change is easily reversible i.e original substance can be recovered.

Chemical Change

• When a substance undergoes a chemical change, its molecular composition is changed entirely. Thus, chemical changes involve the formation of new substances.
• .A chemical change is a permanent change.
• Chemical change both physical and chemical properties of the substance including its composition
• During a chemical reaction, absorption and evolution of energy take place.
• A few examples of chemical change are digestion of food, burning of coal, rusting, etc.
• A chemical change is always accompanied by one or more new substance(s).
• Chemical changes are irreversible i.e. original substance cannot be recovered.