Which of the following represents an endothermic reaction?

An endothermic reaction is defined as a process that absorbs heat from its surroundings, leading to a decrease in temperature in the surrounding environment. This energy absorption is usually necessary to break bonds in the reactants, allowing the reaction to proceed. In such reactions, the enthalpy change (ΔH) is positive, indicating that the energy of the products is greater than that of the reactants.

In this scenario, the option that describes a reaction absorbing heat directly aligns with the definition of an endothermic reaction. It reflects the essential characteristic of these types of reactions, highlighting the relationship between heat transfer and chemical processes. Understanding this concept is crucial for predicting the energy changes associated with different reactions and for determining whether a chemical process will favor the formation of products under given conditions.