Which of the following is NOT a physical change?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. Curdling of milk.
- Curdling of milk is NOT a physical change; it is a chemical change.
- A physical change involves a change in the form or appearance of a substance but does not alter its chemical composition. Examples include melting, freezing, or dissolving.
- A chemical change results in the formation of a new substance with a different chemical composition. Curdling of milk is a chemical change because it involves the conversion of milk proteins (like casein) into curds through the action of acids or bacteria, resulting in a new substance (curd).