What energy change occurs when bonds are formed?

What energy change occurs when bonds are formed?

• A. Exothermic
• B. Endothermic
• C. Isothermal
• D. Entropy-driven

Answer: (A)

Bond formation releases energy because the bonded state is more stable (lower potential energy) than the separated atoms. As electrons are shared or transferred to form the bond, the system moves to a lower energy configuration and the extra energy is emitted as heat to the surroundings. That makes the process exothermic. Breaking bonds, on the other hand, requires energy input (endothermic). Isothermal describes a constant temperature condition, which isn’t what defines the energy change here. Entropy-driven refers to disorder effects rather than the sign of the energy change from bond formation.

Bond formation releases energy because the bonded state is more stable (lower potential energy) than the separated atoms. As electrons are shared or transferred to form the bond, the system moves to a lower energy configuration and the extra energy is emitted as heat to the surroundings. That makes the process exothermic. Breaking bonds, on the other hand, requires energy input (endothermic). Isothermal describes a constant temperature condition, which isn’t what defines the energy change here. Entropy-driven refers to disorder effects rather than the sign of the energy change from bond formation.