The soup at the top gets hot through a convectional current.
It is the process whereby heat travels through liquid media.
When a liquid is heated, its density decreases.
Thus, when the soup at the bottom of a pot is heated, it becomes lighter and floats to the surface of the soup while the soup at the top sinks to the bottom.
When the temperature of the soup at the bottom exceeds that of the one at the top, the cycle continues and a convectional current is generated until a uniform temperature is reached throughout the soup.
More on convection can be found here: https://brainly.com/question/4138428
