The heating of a spoon in a cup of soup is a heat transfer by:

The heating of a spoon in a cup of soup is best described as conduction. This process occurs when heat is transferred through a solid material due to a temperature difference between two areas. In this scenario, the spoon, when placed in the hot soup, has its molecules at a higher temperature due to the heat from the soup. The heat energy moves through the spoon, causing it to warm up.

Conduction is characterized by the direct contact between the hot particles of the soup and the cooler particles of the spoon, allowing for efficient energy transfer. The molecular agitation in the hot soup is transferred to the molecules of the spoon, causing the spoon to heat up.

In contrast, convection involves the movement of fluids (gases or liquids) where warmer, less dense regions rise while cooler, denser regions sink, creating a cycle of heat transfer. Radiation refers to heat transfer through electromagnetic waves and does not require a medium. Direct flame contact implies direct exposure to an open flame, which is not the case with a spoon submerged in soup.