Science (086) — AI-generated practice question

A chemical equation must be balanced to satisfy the Law of Conservation of Mass, which states that mass can neither be created nor destroyed in a chemical reaction. This means the number of atoms of each element must be equal on both the reactant side (LHS) and the product side (RHS) of the equation.

Source: Chapter 1, Section 1.1.2 Balanced Chemical Equations

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• The examiner expects direct reference to the Law of Conservation of Mass — always name it.
• The second point (equal atoms on both sides) is the practical consequence and earns the second mark.
• Do not confuse why we balance (the law) with how we balance (hit-and-trial method) — the question asks only for the reason.