tag:blogger.com,1999:blog-749069622875453742.post-61631014405835828862008-03-11T09:42:00.000-05:002008-03-11T09:42:00.000-05:00Because heat is not matter, it isn’t correct to say it rises or falls. A better way to ask the question is: "Why do hot things (like hot air) rise above cold things (like cold air)?" <BR/>To answer this question, it is important to understand what heat is. <BR/><BR/>Heat is energy. When we say something is hot, we really are saying it has a lot of stored energy. <BR/><BR/>What does this energy do? <BR/><BR/>Matter is made up of incredibly small pieces called atoms and molecules. Atoms and molecules are always moving. <BR/><BR/>The more energy these atoms and molecules have, the faster they move. The faster they mover, the more space they take up. <BR/><BR/>If something is hot, it weighs the same as if it were cold, but it just takes up more space. <BR/><BR/>This leads us to the concept of density. Because hot air takes up more space than cold air, hot air has a smaller density. <BR/><BR/>Less dense hot air will "float" above the more dense cold air.not so BIG ruhhttp://www.blogger.com/profile/12741803724557050968noreply@blogger.com