Final answer:
The statement that all atoms in the reactants of the combustion of methane are present in the products is true and illustrates the conservation of matter, as chemical reactions abide by the law of conservation of mass, with no creation or destruction of atoms.
Step-by-step explanation:
The statement that 'all the atoms in the reactants of the combustion molecules of methane are present in the products of the reaction' is true, which illustrates the conservation of matter. In a chemical reaction, such as the combustion of methane, the law of conservation of mass dictates that matter cannot be created or destroyed. Hence, the number of atoms of each element must remain constant throughout the reaction.
Let's consider the combustion of methane (CH4), which reacts with oxygen (O2) to form carbon dioxide (CO2) and water (H2O). The balanced chemical equation for this reaction is CH4 + 2O2 → CO2 + 2H2O. One can verify the conservation of atoms by counting the atoms of each element on both sides of the chemical equation. For example, there are four hydrogen atoms and one carbon atom in methane, and two oxygen molecules on the reactant side, which rearrange to form one carbon dioxide molecule and two water molecules on the product side. Both sides have the same total count of each type of atom, clearly adhering to the conservation of matter.