Question

Mention three observations from which it may be assumed that a change that is occurring is a chemical
reaction.​

Answer 1

Answer:

change in color, energy change (temperature change or light produced), gas production, formation of precipitate and change in properties.

any three you can write

Answer 2

Three observations from which it may be assumed that a chemical reaction has taken place are-

• Change in color- When fruits ripen, their colour is changed due to chemical reactions inside the fruit.
• Formation of a new substance- During photosynthesis, several chemical reactions occur inside the chlorophyll of leaves that result in the formation of glucose from carbon dioxide and water.
• Evolution of a gas- When fuel burns, a new substance (ash) is formed and gases are released.