Can energy be created or destroyed?

• A. Yes
• B. No
• C. Only in quantum systems
• D. Only in closed systems

Answer: (B)

Energy cannot be created or destroyed; it can only change form or be transferred between objects. The total energy in a system stays constant, as long as you account for all forms and any external inputs or losses. For example, a swinging pendulum swaps potential energy for kinetic energy and back again, with friction turning some of that energy into heat, but the total energy still adds up. A light bulb demonstrates energy transforming from electrical energy into light and thermal energy rather than appearing from nothing. Even in quantum processes, energy conservation holds when you consider the entire system. So the answer is that energy is not created or destroyed.