In thermodynamics, what represents a process with no changes to internal energy?

In thermodynamics, an isothermal process is characterized by maintaining a constant temperature throughout the process. When a system undergoes an isothermal process, any heat added to the system is used entirely to do work, which means that the change in internal energy is zero. This is based on the first law of thermodynamics, which states that the change in internal energy of a closed system is equal to the heat added to the system minus the work done by the system.

During an isothermal process for an ideal gas, the internal energy is primarily a function of temperature. Since the temperature remains constant, the internal energy also remains constant. This means that even if volume or pressure changes during the process (for example, in an ideal gas expanding or compressing), the internal energy does not change.

The other types of processes—adiabatic, isochoric, and isobaric—are characterized by specific conditions that do involve changes in internal energy. In an adiabatic process, no heat is exchanged with the surroundings, and any work done on or by the system will result in changes in internal energy. An isochoric process occurs at a constant volume, meaning no work is done, but changes in temperature due to added or removed heat result