convection, conduction, radiation: a pan is heated on a stove

When a pan is heated on a stove, all three modes of heat transfer - conduction, convection, and radiation - are at play.

1. Conduction: This is the process through which heat is directly transmitted through a substance when there is a difference of temperature between adjoining regions, without movement of the material. When the stove is turned on, heat is conducted from the burner to the base of the pan.

2. Convection: This is the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity, which consequently results in transfer of heat. Inside the pan, as the bottom of the pan gets hot, the particles of the pan (if it's a liquid in the pan) get heated, they start to expand and become less dense. This causes them to rise and the cooler, denser particles to sink. This cycle results in a circular motion known as a convection current, distributing heat throughout the pan.

3. Radiation: This is the emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles that cause ionization. The burner also emits heat in the form of infrared radiation which can add to the heating of the pan.

So, in summary, the pan gets heated through conduction from the direct contact with the stove, the contents of the pan get heated through convection currents, and there is also some radiant heat from the burner to the pan.