Solution:
The above statement is true.The setting of curd is a chemical change because a new substance, lactic acid, is formed. The formed curd has a different taste from the original substance. Casein protein is present in milk, and it reacts with lactic acid. The lactic acid breaks down the chemical structures in milk and forms new ones, resulting in curd, a semi-solid form of milk. Also, it has different smells and chemical properties. After the formation of curd, milk cannot return to its original state. It is an irreversible change.
