What principle states that energy cannot be created or destroyed, only transformed?

The principle that states energy cannot be created or destroyed, only transformed, is indeed the First Law of Thermodynamics. This law emphasizes the conservation of energy within a closed system, indicating that while energy can change forms – such as from kinetic to potential or from thermal to mechanical – the total energy in that system remains constant.

This principle is foundational in understanding various processes in physics, chemistry, and biology, as it lays the groundwork for how energy flows and transforms in different systems. For instance, in biological systems, the conversion of glucose into ATP during cellular respiration exemplifies this transformation of energy.

In contrast, the other principles mentioned do not pertain to the conservation of energy in this manner. The Laws of Motion are concerned with the relationship between the motion of an object and the forces acting on it, while the Second Law of Thermodynamics deals with the direction of energy transformations and the concept of entropy. Quantum Mechanics, on the other hand, focuses on the behavior of matter and energy at very small scales, but does not specifically address the principle of energy conservation as outlined in the First Law of Thermodynamics.