Final answer:
Pouring milk on oatmeal and beating an egg both initially involve physical changes, as they alter the form or appearance without changing the chemical composition. However, beating an egg often precedes cooking, which would then involve a chemical change. Neither process is inherently caused by heating or cooling.
Step-by-step explanation:
When comparing the two processes of pouring milk on oatmeal and beating an egg, we can identify certain similarities and differences in their nature. Pouring milk on oatmeal does not change the chemical structure of either the milk or the oatmeal, therefore it is considered a physical change. However, when you beat an egg, it might be a bit more complex. By itself, beating an egg is essentially a physical change because it involves changing the appearance and consistency without altering the egg's chemical composition.
However, if we consider the usual purpose behind beating an egg—which is typically followed by cooking it—the process can lead to chemical changes as the proteins denature and new bonds are formed when the egg is heated. If we ignore the heating aspect and just focus on the action of beating, no chemical change has occurred. It's important to note that neither process is directly caused by heating or cooling; those are separate actions that may follow but are not part of the initial changes listed.