A reaction that absorbs energy from the surroundings is called

• A. Exothermic
• B. Catalytic
• C. Equilibrium
• D. Endothermic

Answer: (D)

A reaction that absorbs energy from the surroundings gains energy from outside, so the energy change (enthalpy) is positive. This is called endothermic. You can think of it like when you heat ice to melt it—the system (ice) takes in heat from the surroundings, so the surrounding temperature drops a bit. Endothermic processes include melting, photosynthesis, and many dissolution processes that pull heat in.

In contrast, an exothermic reaction releases energy to the surroundings, warming them. A catalytic change speeds up the reaction but doesn’t by itself determine whether energy is absorbed or released. Equilibrium describes a state where forward and reverse reaction rates balance, not the direction of energy flow. So the term that best fits a reaction that absorbs energy from the surroundings is endothermic.