What is the relationship between the energy stored in the log and the energy released during burning?

The energy stored in a log primarily comes from the organic compounds within the wood, particularly carbohydrates like cellulose, which are formed through the process of photosynthesis. When the log burns, this stored energy is released, typically in the form of heat and light.

The combustion process is a chemical reaction where the carbon compounds in the wood react with oxygen to produce carbon dioxide, water, and energy. In this reaction, the total energy contained in the products (carbon dioxide and water) is always less than the total energy present in the reactants (the wood and oxygen). However, according to the law of conservation of energy, the energy that is released during burning matches the energy that was originally stored in the log. This means that when the log combusts, it releases an amount of energy that is equal to the energy that was stored within it in the form of chemical bonds.

Thus, the relationship here is one of equality; the energy released during the process of burning the log corresponds directly to the energy stored in it prior to combustion.