Final answer:
The molecules of the substance in the gas state continued to move randomly and rapidly in the morning due to their kinetic energy, with no net diffusion occurring as they were evenly distributed.
Step-by-step explanation:
The question pertains to the movement of molecules within a substance that was initially in a tank and later became a gas. When energy was transferred out of the substance overnight, the temperature decreased. As a result, in the morning, the substance was found in the gaseous state, indicating that the molecules had absorbed enough energy to overcome their intermolecular forces, allowing them to move freely and fill the space of their container.
Even though the energy was lost during the night, the substance's molecules in the gaseous state still display random and rapid movement due to their innate kinetic energy, but there would be no net movement or diffusion since the molecules are already evenly distributed in the gaseous state.