Question

Select the correct answer from the choices A, B, C, and D which are given. Write only the letter corresponding to the correct answer.

Which of the following is not a physical change?

• A. Grating cheese
• B. Fermenting of cheese
• C. Melting cheese
• D. Mixing two cheeses in a bowl.

Answer 1

The correct option is B

Fermenting of cheese

Explanation for correct option:

Option B

Chemical change:

• A chemical change is a permanent change in which new substances are formed.
• The chemical change is permanent and cannot be reversed by a simple physical method.
• A chemical change involves an exchange of energy in the form of heat or light.
• For example, rusting of iron, burning of wood, respiration, etc.
• Fermenting of cheese is a chemical change.
• During the fermentation new substances are formed.

Therefore, option B is correct.

Explanation for incorrect options:

• Grating cheese, melting cheese, and mixing two slices of cheese in a bowl are physical changes.
• No new substances are formed during these changes.

Physical change:

• A physical change is a change in which no new substance is formed.
• A physical change is temporary and reversible.
• In a physical change, the chemical composition of the original substance is not altered.

Therefore, options A, C, and D are incorrect options.