4.Thermodynamic energy(热力学能) thermodynamic energy (U):the total of all the forms the kinetic energy due to the motion of particles(translational, rotational,vibrational)and the potential energy associated with the vibrational and electric energy of atoms within molecules or crystals )of energy contained within a system.U is also called the internal energy )U is a state function. Molorined stimer U2-U1=△U hs别n 0,e eatonctarte Change in internal energy aU depend only on initial state and a final state of a system and is independent of the path between the two states.thermodynamic energy (U): the total of all the forms ( ) of energy contained within a system. U is also called the internal energy (内能). U is a state function. U2 U1  U Change in internal energy ΔU depend only on an initial state and a final state of a system and is independent of the path between the two states. the kinetic energy due to the motion of particles (translational, rotational, vibrational) and the potential energy associated with the vibrational and electric energy of atoms within molecules or crystals 4. Thermodynamic energy (热力学能)