When a log burns, which statement is true about energy and matter?

In the process of burning, a log undergoes a chemical reaction known as combustion. During this reaction, the log (made primarily of carbon and other elements) reacts with oxygen in the air to produce heat, light, carbon dioxide, water vapor, and other substances.

The principle of conservation of energy states that energy cannot be created or destroyed; it can only be transformed from one form to another. In this case, the chemical potential energy stored in the log is converted into thermal energy (heat) and light energy during combustion. Thus, the total energy remains constant throughout the process.

Similarly, matter is also conserved in this reaction. The atoms present in the original log and the oxygen combine and rearrange to form new substances (carbon dioxide, water vapor, and ash) but do not vanish. The total number of atoms before and after the reaction remains the same, adhering to the law of conservation of mass.

This dual conservation of energy and matter during the burning of a log emphasizes fundamental principles in physics and chemistry. Therefore, the statement that both energy and matter are conserved is accurate and reflects the underlying principles at play during the combustion process.