Question

Q-2 List four observations that help us to determine whether a chemical reaction has taken place.​

Answer 1

Answer:

1)Change of the temperature.

2) Change of the mass.

3)Change of colour, physical state or smell.

4) Generation of noise.

Answer 2

Explanation:

(i) Evolution of a gas (ii) Change in temperature (iii) Change in state (iv) Change in colour.