Which law states that energy cannot be created or destroyed?

The correct answer is the Law of Conservation of Energy, which stipulates that energy in a closed system remains constant; it can neither be created nor destroyed, only transformed from one form to another. This fundamental principle is pivotal in various scientific disciplines, especially within thermodynamics and physics, as it applies to processes involving mechanical, thermal, and chemical energy.

For instance, when chemical reactions occur, the total energy of the reactants will equal the total energy of the products, although the forms of energy may change (e.g., from potential energy in chemical bonds to kinetic energy). This law is essential for understanding energy transfer in physical systems, ensuring that the total energy remains balanced.

The Law of Conservation of Mass, while related, specifically states that mass cannot be created or destroyed in a closed system during chemical reactions. The Law of Thermodynamics encompasses multiple principles, including the conservation of energy, but is not a singular law that defines just that concept. The Law of Common Interaction is not a recognized scientific law in the context of energy or mass.