The term 'energy transfer' in chemistry refers to which of the following?

• A. Energy is created during the reaction.
• B. Energy is transferred as heat or light.
• C. Energy never changes during a reaction.
• D. Energy is stored without transfer.

Answer: (B)

Energy transfer in chemistry describes energy moving between the reacting substances and their surroundings. This often shows up as heat flowing to or from the surroundings, and sometimes as light being emitted or absorbed. The idea that energy is transferred as heat or light best captures what actually happens in reactions, including exothermic ones that release heat (and may emit light) and endothermic ones where heat moves into the system. The other statements contradict how energy behaves: energy isn’t created during a reaction, it can change form and move between objects, and it isn’t simply stored without transfer.