When wood burns in a campfire, which energy transformation occurs?

• A. Chemical energy to Heat and Light
• B. Heat energy to Chemical energy
• C. Electrical energy to Chemical energy
• D. Light energy to Mechanical energy

Answer: (A)

Wood stores chemical energy in its molecular bonds, and when it burns in a campfire that chemical energy is released as heat and light. The fire is a combustion reaction with oxygen, and the energy liberated mainly warms the surroundings and produces visible flames. Some energy also radiates as infrared heat and, to a lesser extent, as sound, but the dominant change is chemical energy turning into thermal energy and radiant energy. Other options would require different processes (for example, adding energy to wood to create new chemical bonds, or using electricity or light to drive motion), which isn’t what happens in a typical campfire.