Question

Classify the following as chemical or physical changes: Burning of paper and wood.

Answer 1

Physical change :

• A change in which a substance undergoes a change in its physical properties i,e shape, size, color, state, or appearance of the substance change is called a physical change, which is generally reversible in nature.
• In these physical changes, the chemical composition remains intact and no new substance gets formed.

Chemical change :

• A change in which the chemical properties of a substance get altered is called a chemical change.
• The chemical change is also called as a chemical reaction which is generally irreversible in nature.
• In a chemical change, one or more new substances always get formed during the reaction.

Burning of paper and wood:

• The burning of paper and wood is known as an example of a chemical change.
• Because here, on heating paper or wood, ash is obtained which has a different chemical composition than that of paper or wood.
• Also, the process is irreversible as we can't obtain paper again from ash.

Hence, the burning of paper and wood is a chemical change.