In thermodynamics, what does the symbol ∆U represent?

The symbol ∆U represents the change in internal energy of a system in thermodynamics. Internal energy is a fundamental property of a system, encompassing the energy due to both the kinetic and potential energies of the particles within the system. It reflects the total energy contained within the system.

When analyzing thermodynamic processes, this change in internal energy is linked to heat exchange and work done on or by the system, as expressed in the first law of thermodynamics, which states that the change in internal energy (∆U) is equal to the heat added to the system (Q) minus the work done by the system (W). Therefore, ∆U is a critical factor in understanding energy transformations in a variety of physical and chemical processes, making it essential for analyzing and predicting system behavior.

The other options relate to different concepts in thermodynamics, such as work done or heat transfer, but do not specifically define what ∆U represents.