Convection and Heat Transfer

I can explain how heat is transferred.

I can explain how convection currents form.

I can describe convection currents in the mantle.

Heat from the sun

Heat you feel around a flame.

Heat you feel from a lamp.

JUST REMEMBER...

Heat from the flame transfers to the pot when pot is placed on flame.

Heat is transferred from the coffee cup to the persons hand.

Heat from soup is transferred to spoon and from the spoon to his hand.

Heat from the sand is moved to feet.

Why do you think heating units or vents are best located near the floor?

So that heat rises throughout the whole room.

How does heat transfer by convection occur?

What happens to particles of an object when they are heated?

The speed up, vibrate and bump into other particles causing them to heat up also.

when a liquid or gas is heated, the particles move faster and spread a part. As a result, the particles of heated fluid occupy more space. The fluid's density decreases. BUT when a fluid cools, its particles move more slowly and settle together more closely. As the fluid cools, its density increases.

How does the density of most substances change when the substance is heated?

The density decreases because the molecules move further apart.

Why do less dense substances rise?

Gravity pulls everything towards the center of the Earth. Denser material is pulled harder, forcing less dense material upward.

What is a current?

How could you stop a convection current?

CONVECTION CURRENTS CONTINUE AS LONG AS HEAT IS ADDED!

How are you experiencing heat transfer right now?

Pair-Up and discuss the question.

Explain how each is an example of heat transfer.

Convection Currents also occur in the outer core. These convection currents cause Earth's magnetic field.

Heat from the core and mantle cause convection currents in the mantle.

Heat Transfer & Convection Currents

Describe Convection Currents in the Mantle.

I Can Statements

Bell Ringer

Hold an ice cube in your hand for one minute. Observe what happens.

Heat always moves from a warmer substance to a cooler substance.

What are some examples of heat transfer by convection?

Is heat moving from the ice cube to your hand or is heat moving from your hand to the ice cube? Why?

Describe convection.

What are three ways that heat is transferred?

Describe radiation.

radiation, conduction, and convection

What are some examples of radiation?

Radiation is the transfer of energy through space.

Convection is heat transfer by the movement of currents within fluid (liquids or gases).

Describe conduction.

Convection is caused by differences in temperature and density within a fluid.

There is no direct contact between the heat source and an object.

During convection, heated particles of fluid begin to flow. The flow transfers heat from one part of the fluid to another.

What are some examples of conduction?

Heat transfer within a material or between a heat source and an object.

Heat transfer by touch!

Many geologists think that hot mantle rock rises from the bottom of the mantle to the top. The hot rock eventually cools and sinks back to the bottom. This cycle continues over and over.

A Constant Flow!

Describe Convection Currents.

I can describe convection currents in the mantle.

A convection current is the flow that transfers heat within a fluid (liquid or gas).

Heating and cooling of the fluid, changes the density and the force of gravity to set the currents in motion.