What does the law of conservation of energy state?

• A. Energy cannot be transferred between objects
• B. Energy is destroyed in closed systems
• C. Energy is created in chemical reactions
• D. Energy cannot be created or destroyed, but it can be transferred from one form to another

Answer: (D)

Energy can be stored in different forms and can move between objects, but in a closed system the total amount of energy stays the same. It may change from one form to another—like potential energy turning into kinetic energy as something falls, or electrical energy becoming light and thermal energy in a bulb—yet the sum of all forms remains constant. That’s why this statement is the best: energy cannot be created or destroyed, it can only be transformed or transferred.

The other ideas don’t fit because energy does transfer between objects, and energy is not destroyed or created out of nothing—energy is conserved while its form changes.