What characterizes an endothermic reaction?

An endothermic reaction is characterized by the absorption of heat from its surroundings. During an endothermic process, the system takes in energy, usually in the form of heat, which leads to a decrease in the temperature of the surroundings. This energy uptake is necessary for the reaction to proceed, as the reactants require this energy to break bonds and form new products. Thus, the reaction results in products that have higher enthalpy compared to the reactants.

In contrast, exothermic reactions release heat, which raises the temperature of the surroundings. The concept of spontaneity is unrelated to whether a reaction is endothermic or exothermic, as spontaneous reactions can be endothermic under certain conditions if they increase the overall entropy of the system. The option regarding no change in temperature does not accurately describe endothermic reactions, as they typically involve a temperature decrease in the environment as heat is absorbed.