An exothermic process is one that:

• A. Releases energy
• B. Absorbs energy
• C. Changes color
• D. Requires a catalyst

Answer: (A)

An exothermic process is defined by energy moving out of the system and into the surroundings. In these processes the overall energy change is negative because the energy released when bonds form is greater than the energy needed to break bonds, so heat (and sometimes light) is given off to the surroundings. That’s why the correct description is that energy is released.

The other features aren’t defining characteristics of exothermic versus endothermic changes. Absorbing energy describes endothermic processes. Changes in color or the need for a catalyst aren’t reliable indicators of whether heat is released or absorbed—they can occur for many reasons and don’t determine the direction of energy flow.