Law of Conservation of Mass: Mass is conserved in a chemical reaction, as shown in the combustion of methane.
Chemical equation illustrating the Law of Conservation of Mass, showing methane (CH₄) reacting with oxygen (O₂) to produce carbon dioxide (CO₂) and water (H₂O), with masses labeled as 16g, 64g, 44g, and an unknown value, totaling 80g on both sides.