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and gases. Examples of conduction are metal spoon in a pan of hot soup, putting your hand on a
stove burner and transfer energy from the stove to the food in pots and pans.

Figure 1.12: Conduction – Energy is transferred by direct contact

Convection

Convection is the up and down movement of molecules within fluids (i.e. liquids and gases) caused
by heat transfer. Convection occurs when warmer areas of a liquid or gas rise to cooler areas in the

liquid or gas because a fluid becomes less dense when heated and therefore rises. Cooler liquid or
gas then takes the place of the warmer areas which have risen higher. This results in a continuous

circulation pattern. Figure 6.13 show water boiling in a pan applying convection method. Examples
of convection hot air balloon, and warmer water at the surface of lake or swimming pool. Another

good example of convection is in the atmosphere. The earth's surface is warmed by the sun, the
warm air rises and cool air moves in.

Figure 1.13: Convection- Energy is transferred by the mass motion of molecules

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