Question

C. Tick the most appropriate answer:

(v) A lot of heat energy is usually absorbed or given out during a

• A. physical change
• B. chemical change
• C. both (a) and (b)
• D. none of these

Answer 1

The correct option is B

chemical change

Part 1: Physical Change

• A change where no new substances are formed but there is a change in the physical appearance of the substance is called a physical change. During a physical change, a only small amount of heat energy is absorbed or given out.

Part 2: Chemical Change

Any change that involves a chemical reaction where one or more chemical substances react and result in the formation of one or more new and different chemical substances is called a chemical change.

• During a chemical reaction, a lot of energy is either absorbed or released, generally in the form of heat energy. This occurs due to the breaking or making of the bond, which results in the formation of new substances.
• The chemical reactions which proceed with the release of heat energy are called exothermic reactions.
• The chemical reactions which proceed with the absorption of heat energy are called endothermic reactions.

Hence, the correct answer is an option (B).