What does the first law of thermodynamics state about energy?

The first law of thermodynamics, often referred to as the law of conservation of energy, states that energy cannot be created or destroyed; it can only be transformed from one form to another. This principle means that the total energy in a closed system remains constant. For example, when a fuel is burned, the chemical energy stored in the fuel is converted into thermal energy (heat) and often mechanical energy (movement), but the total amount of energy before and after the transformation remains the same.

This law is fundamental to understanding various physical processes, such as engines, refrigerators, and even biological systems. It emphasizes the interconnectedness of different forms of energy and how they can be converted, rather than being gained or lost. The idea of energy transformation is critical in fields like physics, chemistry, and engineering, where energy changes are key to understanding system behavior.