AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
The Law of Conservation of Mass makes it necessary to balance a chemical equation, as mass can neither be created nor destroyed in a chemical reaction.
Source: Chapter 1, Section 1.1.2 Balanced Chemical Equations
Examiners expect the exact law name and a brief reason. "Mass is neither created nor destroyed" is the key phrase from the textbook. Do not just write the law name without the reason — that risks losing the mark.