Chapter 5, Lesson 1

Convection and the Mantle

Chapter 5, Lesson 1

Pages 184-187

How is Heat Transferred?

When an object is heated, the particles that make up the the object move faster - these particles have more energy

Heat Transfer - the movement of energy from warmer objects to cooler objects

There are three types of heat transfer: radiation, convection, and conduction

Radiation - the transfer of heat energy that is carried in rays like light

Radiation

Conduction - heat transfer between materials that are touching

Conduction

Convection - heat transfer by the movement of a fluid

**Remember air is a fluid, too

Convection

Multiple Choice

Which type of heat transfer is roasting a marshmallow over a campfire?

• convection

• conduction

• radiation

Multiple Choice

Which type of heat transfer is frying eggs in a metal pan?

• convection

• conduction

• radiation

Multiple Choice

Which type of heat transfer is heating a pot of soup on a stove?

• convection

• conduction

• radiation

Convection Currents

Convection currents cause whatever is closest to the heat to get hot and expand. As it expands, its density decreases causing the hotter part to rise

Density - a measure of how much mass there is in a given volume of a substance

Convection Currents

As the heating and cooling cycle continues, a constant flow begins

Convection Current - flow that transfers heat within a fluid

Heating and cooling of a fluid, changes in the fluid's density, and the force of gravity combine to set convection currents in motion

Convection Currents in Earth

Inside Earth, heat from the core acts like the stove burner

Heat released from Earth's core drives convection currents throughout the mantle and the crust

There are also convection currents in the core that cause Earth's magnetic field

Open Ended

Where does heat come from that drives this convection current in the mantle?

Multiple Select

At which point(s) is the temperature of the mantle greater?

• A

• B

• C

• D

Multiple Select

At which point(s) is the density of the material greatest?

• A

• B

• C

• D

Open Ended

What causes the convection cell to turn to the left at point B?

Open Ended

What happens to the temperature and density of the material between points B and C?

Open Ended

What force causes the convection cell to turn at point C?

Open Ended

What happens to the temperature and density of the material between points D and A?

Open Ended

What causes the convection cell to turn up at point A?

Multiple Choice

How does heat move?

• from a warmer to a cooler object

• from a cooler to a warmer object

• toward a hot object

• away from a cold object

Multiple Choice

How is energy from the sun transferred?

• by radiation

• by conduction

• by convection

• by the force of gravity

Multiple Choice

Heat from which of these causes convection currents inside Earth?

• crust

• crust and mantle

• crust and core

• mantle and core

Multiple Choice

Which of these combines with changes in a fluid's density and the force of gravity to set convection currents in motion?

• evaporation of a fluid

• condensation of a fluid

• freezing and melting of a solid

• heating and cooling of a fluid