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 name of the law. You may add a one-line explanation (atoms of each element must be equal on both sides) to complete the answer. Do not write more than one sentence for a 1-mark question.