The student quickly discovers that placing the marshmallow over the flame is more effective than heating the marshmallow on the side of the flame. According to the information above, what type of heat transfer is present when the marshmallow is above the fire that is not present when the marshmallow is on the side of the fire

The answer is convection.

Explanation:

There are three types of heat transfer: conduction, convection and radiation.

Conduction occurs when two objects touch each other and transfer heat. Convection occurs when an object heats its surrounding fluid (like air, or water) and, since the hot fluids are less dense than the cold ones, they go up. So convection is a type of heat transfer that usually goes from down to up. Radiation occurs when objects emanate heat in the form of electromagnetic waves that propagates in all directions.

So in this case, when the marshmallow is above the fire, it is exposed to convection, which does not occur when it is on the side of the fire.