1. Heat energy flows from warmer to cooler areas Lesson 1.3 You will learn: How heat is transferred in matter; How the process of conduction transfers heat; How the process of convection transfers heat

3. Heat flow by conduction requires contact  Conduction is the process that moves energy from one object to another when they are touching  Metals are good conductors of heat  Insulators are poor conductor of heat

4. Heat flow by convection involves a flow of matter  Convection is the process that transfers energy from place to place by the motion of a gas or liquid  Convection occurs in fluids

5. Density  A substance’s density is a measure of the amount of mass it contains per unit volume.  The density of substance changes as its temperature changes  Cold liquid is more dense compared to warmer liquid

6. Density and Convection CurrentsDensity and Convection Currents  Convection current is a pattern of movement that occurs when a gas or liquid rises as it becomes warmer in one area and sinks as it becomes cooler in another area