Yes, one of the fundamental principles of thermodynamics is the conservation of energy, which states that energy cannot be created or destroyed in an isolated system. This principle is often referred to as the First Law of Thermodynamics or the Law of Energy Conservation.
According to the First Law of Thermodynamics, the total energy of a closed system remains constant. Energy can be transferred between different forms (such as heat or work), but the total energy content of the system remains unchanged. In other words, the energy of a closed system is conserved.
This law is based on extensive experimental observations and has been found to hold true in a wide range of physical and chemical processes. It is a fundamental principle that underlies many aspects of thermodynamics and has far-reaching implications in various scientific fields.