Question

A small quantity of curd is added to warm milk. The milk is stirred and is set aside for a few hours at a warm place. In a few hours, the milk changes into curd. This is a:-

• A. Physical change
• B. Chemical change
• C. Permanent change
• D. Temporary change

Answer 1

Answer: (B), (C)

The correct options are
B

Chemical change

C

Permanent change

Chemical change:- It is a change in which the chemical composition of the substance changes because of the formation of a new substance. Formation of curd to milk is a chemical change because the chemical composition of milk is changed and new substance, i.e., the curd is formed.
Moreover, it is a permanent change because this change remains fixed and curd cannot be brought back to the initial state, i.e., milk.