Final answer:
The law of conservation of mass states that matter is not created or destroyed, but may change forms. In burning wood, the gases produced plus the ashes left behind equal the original mass of the wood and oxygen, confirming that this law applies.
Step-by-step explanation:
The question asks whether the law of conservation of mass applies to the burning of wood at a campfire, even when several kilograms of wood turn into only a few kilograms of ashes. According to the law of conservation of mass, matter cannot be created or destroyed in a chemical reaction. During the burning of wood, the wood combines with oxygen, resulting in ashes, carbon dioxide, and water vapor. These gases float off into the air, and even though we might see only the ashes left behind, the mass of these gases combined with the mass of the ashes would equal the mass of the original wood and the oxygen consumed by the fire. Therefore, the total mass remains the same before and after the fire, demonstrating that the law of conservation of mass is indeed upheld during the process of burning wood.