What describes an endothermic reaction?

An endothermic reaction is characterized by the absorption of energy from its surroundings. This means that during the reaction, the system takes in heat, resulting in a temperature decrease in the surrounding environment. Common examples include the process of photosynthesis and the melting of ice. In these cases, energy is required for the reaction to proceed, which is why you often feel a cooling effect when endothermic reactions occur.

This concept is crucial because it helps to understand thermodynamics and energy transfers in chemical processes. Endothermic reactions contrast with exothermic reactions, which release energy, making option B the clear choice for describing an endothermic reaction accurately.