Internal Energy

Internal energy is the total energy contained within a system, reflecting the energy of its microscopic components, including atoms and molecules. This energy arises from two main sources: the kinetic energy of particles in motion and the potential energy due to the interactions between them. In thermodynamics, changes in internal energy are crucial for understanding how a system exchanges heat and work with its surroundings. For example, when you heat a substance, its internal energy increases, often leading to changes in temperature or phase, like melting or boiling.