When milk is converted into curd, what type of change is it?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. Chemical Change.
When milk is converted into curd, it undergoes a chemical change. This happens because the bacteria in curd culture ferment the lactose (milk sugar) into lactic acid, which causes the milk proteins to coagulate and form a semi-solid substance called curd. This process changes the chemical composition of milk, making it thicker and sour in taste. Unlike physical changes, this transformation is irreversible under normal conditions, indicating a chemical change.