Answer: released to; absorbed from
- In an exothermic reaction, energy is released to the surroundings.
- In an endothermic reaction, energy is absorbed from the surroundings.
Explanation:
An exothermic reaction is a chemical reaction that occurs spontaneously and brings about the release of energy to the surroundings. Hence, the reacting vessel feels hot as the reaction proceeds.
An endothermic reaction, on the other hand, does not occur spontaneously and proceed only when energy is absorbed from the surroundings. Hence, the reacting vessel feels cold as the reaction proceeds.