Chapter 7 Heat Transfer

Convection Currents and the Mantle What will we learn: 1.How is heat transferred? 2.What causes convection currents?

vocab: 1.heat transfer – when energy moves from a warmer object to a cooler object (water in ice cube tray transfers heat to inside of freezer).

2.radiation – heat transfer that requires NO direct contact between a heat source and an object. (sunlight, campfire) 3.conduction – heat transfer by direct contact of molecules of matter. (pot to soup spoon)

Convection Heat transfer by movement of a fluid (liquid or gas) Example: upstairs of house is warmer than downstairs Warmer, less dense air rises; colder, more dense air sinks

5.convection current – created when there are differences in temperatures and densities within fluids (liquid or gas).

The temperature difference between the bottom and the top of the mantle are what creates the current. THIS IS WHAT MOVES THE PLATES!