According to the law of conservation of matter, we know that the total number of atoms does not change in a chemical reaction and thus mass is conserved. The reactant in this model is hydrogen peroxide. Hydrogen peroxide decomposes to produce water and oxygen gas. How many water molecules must be added to complete this model?
In a chemical reaction the total mass of all the substances taking part in the reaction remains the same. Also, the number of atoms in a reaction remains the same. Mass cannot be created or destroyed in a chemical reaction.
