Chapter 8 – Energy Transfer and Conservation
Introduction
 What does “transfer” mean?
 Movement of energy from one place to another without
a change in form
 What does “transformation” mean?
 Process changing from one form of energy to another
 Are they the same thing?
KEY QUESTION
How does the transfer of
energy affect natural
and human-built
environment?
Natural vs. Human-Built
 How do natural environments differ from human-built
environments?
 Natural environments are living and non-living things
that occur naturally; human-built environments have
been invented and built by people
Natural and Human-Made
 What are some examples of things and processes that
occur in our natural environment?
 Oceans, mountains, the wind, water, sunlight, etc.
 What are some examples of things and processes that
that are human-built?
 Bridges, cars, coffee cups, etc.
8.1 Thermal Energy Transfer
 What is the definition of thermal energy?
 Thermal Energy: the total kinetic energy and energy of
attraction of all the particles of a material
 we can increase the thermal energy of a substance by
heating it
 We can decrease the thermal energy of a substance by
cooling it
 Changes in thermal energy can cause a substance to
change states (solid to liquid, etc.)
What if…?
 What would life be like if we didn’t have refrigerators,
air conditioners, and heaters?
 Read page 203
8.3 Conduction
 Figure 1 on page 206
 What is happening? Explain.
Conduction
 Conduction: the transfer of thermal energy through a
substance, or between substances in contact, by the
collision of particles
 Particles must collide in order for thermal energy to be
transferred by conduction
Question…
 Can conduction occur between two objects that are
not touching or connected in some way?
 No…conduction can only occur between two objects or
substances that are touching.
 Read page 206 and 207
8.4 Conduction and Geological
Processes
 Trivia: What is the Earth made up of?
 The mantle is almost entirely solid rock. It contains a
small amount of molten rock, but the vast majority is
solid.
 What does “geological” mean?
 Having to do with the Earth and rocks
 How might conduction effect geological processes?
Geothermal Energy
 Geothermal Energy: is energy contained below the
Earth’s surface
 Read top of page 208
Volcanic Eruptions
 The volcanic eruptions that cause hot magma to be
pushed to Earth’s surface are not caused by
conduction; the magma rises toward the surface
because it is less dense than the surrounding rock.
 Magma is often under pressure because it is in tight
spaces when it is heated.
 Magma and lava lose a lot of thermal energy through
conduction into the surrounding rocks or air.
Heat and Rock Formation
 Igneous rock: rock formed from magma that has
cooled and solidified
 Metamorphic rock: rock that is formed when heat and
pressure change existing rock
Heat and Rock Formation
 Once the rock is exposed to high temperature and
pressure, thermal energy is transferred to the rock by
conduction
 This causes the particles of the rock to be rearranged,
resulting in the formation of metamorphic rock,
including diamonds
Diamonds
 Form deep in the Earth’s crust
 Heat and pressure may change substances into
diamond
 Metamorphic rock

8.5 Convection
 Convection: the transfer of thermal energy from one
part of a fluid to another by circulating current of
faster-moving and slower-moving particles
 Convection occurs in a fluid whenever warmer fluid
exists below cooler fluid.
 Heating fluid from below causes convection because it
produces an area of warm fluid at the nottom of an area
of cooler fluid.
Steps to heating a pot of soup on the
stove…
 Groups of 3 or 4
 Arrange the steps in the correct order
Figure 1 on page 210…
 What is happening when this pot of soup is heated?
 Read page 210 and 211
8.6 Convection in the Environment
 What did you notice during the last thunderstorm we
had/you remember?
 What were the conditions before the storm?
 Why do thunderstorms happen?
 Occur largely because of the effects of convection in the
atmosphere
 Change in temperatures
What is convection and conduction?
 Convection: the transfer of thermal energy from one
part of a fluid to another by circulating current of
faster-moving and slower-moving particles
 Conduction: the transfer of thermal energy through a
substance, or between substances in contact, by the
collision of particles
Thunderstorms
 Thunder and lightening
 Can lead to hail, tornados, and hurricanes
 The Earth’s surface is heated by the sun
 Energy is transferred to the air by conduction
 The warm air is pushed up higher
 Large puffy clouds appear
 A lot of thermal energy released
Read top of page 213
8.7 Radiation
 What is our major source of energy?
 The Sun
 Conduction and convection can only occur when
matter is present
 In this section, we will learn about the third type of
energy transfer that does not require the presence of
matter
Energy Transfer
 Radiant Energy: energy that travels in the form of
electromagnetic waves through empty space; includes
visible light, ultraviolet rays, and infrared rays
 Radiation: the transfer of radiant energy by means of
electromagnetic waves
 Hair straightener activity
 Read page 214 and 215
UV Rays
What colour attracts the sun?
8.8 Managing the Transfer of
Thermal Energy
 What are the three methods of energy transfer?
 Conduction – transfers thermal energy through walls
 Convection – currents produced by heaters warm the
rooms
 Radiation – from the Sun; energy can be transferred to
roofs through electromagnetic rays
Our School
 What are some components of the school that work
together to transfer energy throughout the school?
 Walls, roof, lights, air vents, floors, windows, doors, custodians, etc.
 What happens when a building is poorly designed?
 Some areas may be really hot and some may be very cold
 Expensive to heat because of poor insulation
Read page 217
Thermal Energy Transfer
 What are ways we can reduce thermal energy transfer?
 Caulking gaps
 Replace old furnaces
 Closing blinds on sunny days
 Open windows at night to bring in cooler air
Preventing Conduction
 Use insulating materials
 The higher the R-Value, the more difficult it is for
energy to move through the material
Insulation material
(2.5 cm thick)
wood
fibreglass batt
cellulose
polystyrene foam
board
R-Value
0.71–1.41
3.2–3.6
3.1–3.7
3.6-5.0
Green Roofs
 10% reduction in heat costs during the winter
 25% saving in air conditioning costs in the summer
 Read page 218 - 220