Heat is transferred between two objects that are in contact with each other through conduction. When a pan containing uncooked meat is placed on a heated electric stove, heat transfers from the stove to the pan and the meat. The transfer can be detected as a rise in temperature in the meat as it cooks. This is one of the simplest demonstrations of heat conduction.
There are three main forms of heat transfer. Conduction requires contact between the molecules of the objects involved. Convection and radiation can transfer heat without physical contact between the object and the heat source. In conduction, heat is transferred from one molecule to the next, thus spreading gradually from the heat source through the entire object over time.
Conduction can be demonstrated through a simple experiment using household objects. Wax drops can be placed at equal distances along the length of the handle of a metal spatula. One end of the spatula should be placed on a heat source, such as a stove. As heat transfers from the stove to various parts of the spatula, the wax drops melt in succession, starting with the drops closest to the heat source. The wax that is furthest away from the heat source melts last. This is because the molecules closest to the stove heat up first, thus melting the wax drops closest to them. The heat is then transferred from one molecule to another further away from the stove until the entire spatula is heated to the same temperature as the heat source.