Final answer:
Burning wood demonstrates that wood contains potential energy, which is released as thermal energy during combustion. This conversion of potential energy to heat is a fundamental aspect of burning biomass, such as wood.
Step-by-step explanation:
Burning wood is evidence that wood contains potential energy that can be converted into heat. This is because the process of burning, also known as combustion, involves a chemical reaction wherein the chemical energy stored in the wood's molecules is released as thermal energy. When wood burns, its carbon content combines with oxygen to form carbon dioxide, releasing a significant amount of thermal energy, a process described in Chapter 9 of the reference material. This chemical energy is a form of potential energy because it is stored within the substance and only released during a chemical reaction.
It's worth noting that the principle of conservation of energy dictates that no new energy is created during the burning process, which means option 4 is incorrect. It's also not just the density and weight (option 1) or only kinetic energy (option 2) that are responsible for the release of energy. The burning of biomass, such as wood, is a common method for releasing the stored chemical energy as heat, which can be used for heating and cooking, as mentioned in Chapter 14.4 of the reference material.