Question

2. Why energy is involved in a chemical change ?
3. What do you understand by 'chemical reaction' ?​

Answer 1

Answer:

2. Chemical energy

3.The process by which atoms of one or more substances are rearranged to form different or new substances

Answer 2

Answer:

2. In a chemical change there is either a release of energy or absorption of energy. So changes are classified as exothermic and endothermic.

3. A chemical reaction occurs when one substance reacts with another substance during a chemical change. Eg. Iron reacts with oxygen and moisture to form rust.