Heat and Changing States of Matter - Discovery Education

Heat and Changing States of MatterTHEMESHeat and Changing States of Matterexplores the basic aspects of heatand thermal energy. Heat of fusionand heat of vaporization are covered,in addition to expansion andcontraction. The transfer of heatthrough conduction, convection andradiation are also discussed, as wellas the heat capacity of various typesof matter.OVERVIEWHeat causes matter to change statesthrough expansion or contraction ofmolecules. The amount of motion in amolecule is a reflection of its kineticenergy. Temperature is a measure ofthe average kinetic energy of the moleculesmaking up an object. If weapply thermal energy to a material,we can increase its kinetic energyand cause it to change states. Heat ismeasured in units called calories.Some materials, such as coal, havestored or potential energy. Thisenergy is released as the coal burns.The heat necessary to change a substancefrom a solid to a liquid, withno temperature increase occurring, iscalled the heat of fusion. The heatnecessary to convert boiling water tosteam is called the heat of vaporization.Most materials expand as theyget hotter and contract as they getcooler.OBJECTIVESTo learn more about the characteristicsof heat and thermalenergy.To discuss the various aspects ofconduction, convection and radiation.To examine heat of fusion andheat of vaporization.To better understand how heat ismeasured and controlled.To explore thermal conductanceand heat capacity.© Copyright 1999 AIMS Multimedia Heat and Changing States of Matter11