Heat Energy

     This unit begins with a discussion about matter:  what it is, what it is made up of, and the three phases of matter (solids, liquids, and gases).   We discuss properties of each phase of matter including molecule arrangement and how the molecules in each phase of matter move. 

     We then move on to begin discussion heat and temperature.  Students learn how temperature changes affect matter, and quickly develop an understanding of phase changes (melting, freezing, condensing, evaporating, sublimating).  Students will conduct a lab during which they discover what happens to the temperature of a substance as it undergoes a phase change (they are always very surprised with the results, and often have a hard time believing them).  After completing the lab, students will construct a phase change graph, and will label what is happening at various points along their graphs. 

     Finally, we move on to the rather difficult concepts involved with heat transfer.  Students will learn that heat travels from where there is more of it to where there is less of it.  We discuss conductors and insulators, and then quickly move on to introduce the three types of heat transfer: conduction, convection, and radiation.  Students will learn that conduction involves the direct contact of molecules, and can take place in all three phases of matter.  Convection is caused by density differences in fluids of different temperatures, and involves the rising of warmer fluids  and the sinking of colder fluids (convection can only happen is liquids and gases).  Students will learn that radiation is heat transfer through empty space, and that it can only take place in gases.

     During this unit we will also briefly discuss the differences between physical and chemical changes in substances.