Which of the following accurately defines an endothermic reaction?

An endothermic reaction is defined as a reaction that consumes energy from its surroundings. This means that when the reaction occurs, it absorbs heat or energy, resulting in a temperature drop in the environment around it. This characteristic is crucial in differentiating endothermic reactions from exothermic reactions, which release energy.

In an endothermic process, the energy absorbed is often used to overcome bonds in reactants or to drive the reaction forward. Common examples include photosynthesis and the dissolution of certain salts in water, where the surroundings feel cooler due to the energy intake. Understanding this key aspect of endothermic reactions helps to analyze and predict how they will behave in various chemical processes.

The other definitions focus on different energy signals or conditions that do not capture the essence of endothermic reactions. For instance, reactions that release light involve exothermic processes, and spontaneous reactions do not necessarily require an external energy input, which contrasts with the energy consumption characteristic of an endothermic reaction. Additionally, stating that a reaction occurs only at elevated temperatures does not apply to all endothermic reactions, as they can initiate under various temperature conditions as long as they absorb energy.