When a log burns, does heat and light energy come from the log itself?

When a log burns, the heat and light energy produced actually comes from the chemical reactions occurring within the log as it combusts. The process of burning, or combustion, involves the log reacting with oxygen from the air, breaking down its stored chemical energy, and releasing it in the form of heat and light. This transformation happens because the organic materials in the log, primarily composed of carbon compounds, are oxidized during the reaction, resulting in the release of energy.

The log itself contains energy stored in its chemical bonds, and when those bonds break during combustion, the energy is released. Thus, it is accurate to say that the heat and light energy do come from the log itself as it is transformed through this process.