Heat and Changing States of Matter - Discovery Education

INTRODUCTION TOTHE PROGRAMThe presence of heat on the Earth isthe basis of all life. Heat is one of themost important elements known tohumans. It is used to warm ourhomes, provide us with light, cookour food, and produce fuel used fortransportation and electricity. We cansee basic examples of heat all aroundus. A breeze is created by warm airthat is replaced by cool air. A warmstove heats a room as currents circulatethe warm air. Infrared rays fromthe sun cause our skin to burn. Thesephysical examples of heat are bestunderstood if we examine the aspectsof heat on a molecular level. In fact, itis the increased movement of invisiblemolecules that create heat in all substances.INTRODUCTION TOVOCABULARYBefore starting the program, write theword “thermal” on the board. Whatdoes this word mean to students?Where have they heard this word, orrelated words, before?(Thermal means “relating to orcaused by heat.” Some related wordsinclude: thermal underwear, thermos,thermometer, thermodynamics, thermonuclearand thermostat.)DISCUSSION IDEASThe heat that we use on Earth comesfrom six main sources. Can studentsname all six sources? What are someways that we use heat from thesesources? (The six main sources ofheat are the sun, fire, friction, nuclearenergy, chemical reactions, and heatwithin the Earth. Heat from the sunwarms solar panels that make electricalenergy. Heat from fire is used tocook food and produce fuel. Heatfrom the friction of two sticks rubbingtogether can help us build a campfire.Lighting a match is an exampleof a useful chemical reaction that producesheat. Nuclear energy is used toproduce electricity for heating ourhomes.)FOCUSAsk students to think about the variousapplications of heat. What aresome ways that students used heatbefore getting to class today? Whatwould their day have been like withoutheat? Ask them to keep thesethings in mind as they begin the unit.© Copyright 1999 AIMS Multimedia Heat and Changing States of Matter13