Changes Around Us Physical and Chemical Class 7 Assertion and Reason Questions

Changes Around Us Physical and Chemical Class 7 Assertion and Reason Questions

Changes Around Us Physical and Chemical Class 7 Assertion and Reason Questions

Following questions are of Assertion (A), Reason (R) type questions. Choose the correct answer from the following options.

(a) Both A and R are true, and R is the correct explanation of A.

(b) Both A and R are true, but R is not the correct explanation of A.

(c) A is true, but R is false.

(d) A is false, but R is true.

1. (A): Rusting of iron is a chemical change.

(R): Rusting produces a new substance called iron oxide.

Answer:

(a) Both A and R are true, and R is the correct explanation of A

2. (A): Melting of ice is a physical change.

(R): In melting, no new substance is formed.

Answer:

(a) Both A and R are true, and R is the correct explanation of A

3. (A): Burning of wood is a chemical change.

(R): Burning wood produces ash, smoke, and gases.

Answer:

(a) Both A and R are true, and R is the correct explanation of A

4. (A): Curdling of milk is a physical change.

(R): Curdling involves the formation of curds and whey, which are different substances.

Answer:

(d) A is false, but R is true

5. (A): The process of making popcorn from corn is a chemical change.

(R): The heat causes a change in the chemical structure of the corn kernels.

Answer:

(a) Both A and R are true, and R is the correct explanation of A