Which of the following is NOT a physical change?

Correct option is B

The correct answer is (b) Fermentation of substances.
· Fermentation is a biochemical process where microorganisms like yeast or bacteria convert sugars into alcohol, carbon dioxide, and other byproducts. This is a chemical change because it results in the formation of new substances with different chemical properties.
· Liquefaction of gases to liquids, vaporisation of liquids to gases, and melting of solids to liquids are all physical changes because they involve a change in state without altering the chemical composition of the substances involved.
Information Booster:
· Liquefaction of gases to liquids: This is a physical change where a gas changes into a liquid, typically by cooling or compressing. The chemical identity of the substance remains the same.
· Vaporisation of liquids to gases: This physical change occurs when a liquid is converted into a gas, usually through heating. Again, the substance’s chemical structure does not change.
· Melting of solids to liquids: In this physical change, a solid turns into a liquid upon heating. The process involves a change in state but not in chemical composition.