Welcome to Physics Forums.chocofingers said:hi,
Can anybody explain the phenomenon behind internal energy? and what is the change in internal energy when water evaporates. Please do give reference to first law of thermodynamics.
Thanks in advance.
No. In this case, the potential energy is a negative quantity, analogous to gravitational potential energy. Therefore, breaking molecular bonds increases the potential energy and hence increases the internal energy.chocofingers said:Thank you for the references.
here one of the references says that molecular attractive forces are associated with internal energies also. SO heating water means breaking potential energy bonds and hence decreasing potential energy of the system.thereby the internal energy of the system would reduce ??
Internal energy is the total energy stored within a substance, including the kinetic and potential energies of its molecules. It is a measure of the microscopic energy within a system.
During evaporation, molecules at the surface of a liquid gain enough energy to break free from the liquid and enter the gas phase. This process decreases the internal energy of the liquid as the more energetic molecules leave, resulting in a cooling effect.
The 1st Law of Thermodynamics states that energy cannot be created or destroyed, but can only be transferred or converted from one form to another. This means that the total energy of a closed system remains constant.
The 1st Law of Thermodynamics is directly related to internal energy, as it describes the conservation of energy within a system. The internal energy of a closed system can change through heat transfer, work done, or changes in the system's composition, but the total energy remains constant.
Yes, internal energy can be negative. This occurs when the system loses energy through work done or changes in composition. However, the total energy of the system will still remain constant, as per the 1st Law of Thermodynamics.