Final answer:
When Bela puts an egg in a pan, the egg's thermal energy increases. This is due to the heat transfer from the hot pan to the colder egg, which is consistent with the second law of thermodynamics.
Step-by-step explanation:
When Bela puts an egg in a pan, the thermal energy of the egg increases. This is because heat transfer generally occurs from a hot object to a cold one. In this case, the hot pan transfers heat to the colder egg, causing an increase in the egg's thermal energy. This process adheres to the second law of thermodynamics, which states that in an isolated system, natural processes tend to lead to an increase in entropy or a spread of energy. Thus, the answer is 1) It increases.
Heat flow is also relevant in other examples, such as a pot of water on a hot burner where heat flows from the burner to the water, or uncooked macaroni added to boiling water which receives heat from the water. Understanding the flow of heat can also help to explain changes in the internal energy of a system, like when an ice cube is rubbed against a rough surface, transforming kinetic energy from friction into thermal energy raising the temperature of the ice cube.