Which of the following best describes what happens during an exothermic reaction?

• A. It absorbs energy from the surroundings.
• B. It requires a continuous input of energy to proceed.
• C. It releases energy to the surroundings, usually in the form of heat.
• D. It decreases the temperature of the surroundings.

Answer: (C)

Verified step by step guidance

1. Understand the definition of an exothermic reaction: it is a chemical reaction that releases energy to its surroundings.
2. Recall that energy released in exothermic reactions is often in the form of heat, causing the surroundings to become warmer.
3. Recognize that because energy is released, the system loses energy, which means it does not require continuous input of energy to proceed.
4. Note that since energy is given off, the surroundings gain energy, so the temperature of the surroundings typically increases rather than decreases.
5. Conclude that the best description of an exothermic reaction is that it releases energy to the surroundings, usually as heat.