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1. Heat transfer through conduction, convection and
Radiation.
Grade 7 Science
Concept Presentation
Initha Subramaniam OISE/UT
Instructors: Dr. Marty Zatzman
and Janine Extavour

2. Overview
• Curriculum Expectations.
• Prior knowledge on the topic.
• Misconceptions.
• Demonstrations / Experiments.
• Societal issues that can be discussed in class.
• Safety considerations.
• 5 day lesson plan.
• Placement of the concept within the unit.
• Place in the Curriculum.
• Advance preparations/ materials.
• Assessment (A) Evaluation (E).
• Learning styles (LS) / Multiple intelligence
(MI).
• Differentiated Instruction.
• References

3. Grade 7 Heat Unit
Curriculum Expectations
Fundamental concept: Energy transfer
Big idea: Heat is a form of energy that can be transformed and
transferred. These processes can be explained using the
particle theory of matter.
Overall Expectations:
2. Investigate ways in which heat changes substances, and
describe how heat is transferred.
3. Demonstrate an understanding of heat as a form of energy
that is associated with the movement of particles and
essential to many processes within the earth’s systems.

4. Specific Expectations
3.1 Use the particle theory to compare how heat affects the motion of particles
in solids, liquids and gases.
3.3 Use particle theory to explain the effects of heat on volume of solids, liquids
and gases.
3.4Explain how heat is transmitted through conduction.
3.5 Explain how heat is transmitted through convection.
3.6 Explain how heat is transmitted through radiant energy.
2.4 Use scientific inquiry and experimentation skills to investigate heat transfer
through conduction, convection and radiant energy.
2.5 Use appropriate science and technology vocabulary, including heat,
temperature, conduction, convection and radiation in oral and written
communication.
3.7 Describe the role of radiation in heating and cooling the earth, and explain
how greenhouse gases affect the transmission of radiated heat through the
atmosphere.

5. Grade 9 Earth and Space: Climate Change
Overall expectations:
D1. Analyze some of the effects of climate change around the
world, and assess the effectiveness of initiatives that attempt
to address the issue of climate change.
Specific Expectations:
D3.2 Describe and explain heat transfer in the hydrosphere and
atmosphere and its effects on air and water currents.
D3.3 Describe the natural green house effect.

6. Day 1. solid particles
• Held tightly and packed fairly close together - they
are strongly attracted to each other.
• Have fixed positions but they do vibrate.
• Expands when heated.

7. Liquid Particles
• Fairly close together with some attraction between
them.
• Able to move around in all directions but movement
is limited by attractions between particles

8. Gas Particles
• Have little attraction between them.
• Free to move in all directions and collide with each
other and with the walls of a container and are
widely spaced out.

9. Prior Knowledge
kinetic Energy: All moving objects have this type
of energy.
Particles moving faster = greater kinetic energy.
Particles moving slower = slower kinetic energy.
When particles move and collide they speed up
or slow down.
Temperature: measures the average kinetic
energy of particles

10. What happens when particles are
heated
• When particles are heated they go through a
change of state.
• Heat : Transfer of energy from a particle of a
warmer object to a particle of a cooler object.
• When heating an object energy is transferred
to the particles of the object.

11. Change state of matter
and how is thermal energy transferred
Experiment : Expansion and
Contraction of particles.
Expansion: balloon fasten on a
volumetric flask set inside a
beaker of hot water.
Contraction: Balloon fasten on
a volumetric flask set inside
a beaker of ice water.

12. Note to self
Give the class candies to earn their votes.
Mmmmm ……. Candies make everything better.
You tube http://www.youtube.com/watch?v=VzE_IPedujc&feature=related

13. Day 2: Making soup to demonstrate conduction
Conduction happen when two substances are touching.
The particles of one substance collides with particles
of another substance or with each other. Thermal
energy is transferred. Metals good conductors.

14. Day 3: Convection current when boiling water
Convection is the movement of gases or liquids from a cooler
area to a warmer area.
Example: cooking soup on the stove.
The warmer soup moves up from the heated area at the bottom
of the pan to the top where it is cooler.
The cooler soup then moves down to take the warmer soup's
place. The movement is in a circular pattern within the pan.

15. Day 4: Radiant energy
• Radiation is the transfer of heat energy through empty space.
• Energy travels from the sun to the earth by means of
electromagnetic waves.
• Shorter wavelength = higher energy
• Darker-colored objects absorb more visible radiation thus
becoming good insulators of thermal energy.
• whereas lighter-colored objects reflect more visible radiation.
• Every surface on earth absorbs and reflects energy at varying
degrees, based on its color and texture.

16. Common misconceptions
1. Particles get bigger when they are heated.
2. Convection current forms only when a
substance is boiled.
3. At night time land and water cool down at
the same rate.
4. All dark coloured objects are good insulators
of thermal energy.

17. Misconception 1
Particles get bigger when heated.
• Scientifically incorrect.
• Heat energy flows through a region of high temperature to a
region of low temperature when the particles collide.
• This is the process of conduction.
• When particles carry thermal energy they do not get bigger
but take up more space (expand slightly).

18. Experiment : Testing for particle expansion
Ball and ring experiment to explain conduction.
The sequence used to heat up the objects
1. RT ball and RT ring =
2. Hot ball and RT ring =
3. Hot ball and hot ring =
4. RT ball and hot ring =
Explain the observations in terms of the motion of the metal
particles in the ball and ring.
Make statements describing the sizes in relation to the ball and
ring at different temperatures.
(RT= Room Temperature)

19. Misconception 2
Convection current forms only when a
substance is boiling.
• When fluid or gas particles are warm they expand and
become less dense in mass.
• They rise from the bottom moving upwards towards the
surface .
• As warm particles reach the top layer they push down the
colder particles (greater in mass) down.
• The process continues in a cycle .
• However cooling particles from above will also produce
convection current.
• Both warm gas and fluid particles transfer thermal energy
through convection current.

20. Experiment: Convection in warm water.
• Plastic container with RT water supported by four
Styrofoam cup.
• Place a drop of red food coloring at the bottom of
the water.
• Place blue coloured ice cubes at the top
• Place a cup of hot water at the bottom of the food
coloring.
• Observe and discuss results.

21. Misconception 3
Gases, liquids and solids heat up at the same rate and
release thermal energy at the same rate
Demo = www.youtube.com/watch?v=gM0d3fGew-0

22. Land and Sea Breeze
• Convection currents are noticeable near the ocean, large lake,
or other appreciable area of water.
During the day:
• land heats faster than water, so the air over the land becomes
warmer and less dense.
• It rises and is replaced by cooler, denser air flowing in from
over the water. This causes an onshore wind, called a sea
breeze.
During Night time:
• land cools faster than water.
• warmer air over the water rises and is replaced by the cooler,
denser air from the land, creating an offshore wind called a
land breeze.
• Demo = http://www.youtube.com/watch?v=xlqc3YJAmiQ&feature=related

23. Misconception 4
All black objects are good insulators.
Radiant energy travels through empty space.
For a black coloured object to become an insulator of
thermal energy it as to be left out side in direct view of
sunlight or near a roaring flame but not touching the
flame.
A black coloured object left under room temperature
conditions will not turn into an insulator of thermal
energy.
Ex: A plastic bottle filled with warm water and wrapped in
black cloth will not be a good insulator of thermal
energy.

24. Experiment : Not all black objects are insulators
Part A: students make data tables to record the time and temperature.
• Fill 3 pie pans to the same level, one with dark soil, one with light sand, and
one with water.
• Place the pie pans under a table lamp
• Place a thermometer into each pie pan.
• measures the temperature just under the surface of the substance .
• Record the starting temperatures on the data table.
• Turn on the lamp and record the temperature of each substance every
minute for ten minutes.
• At the end of ten minutes, turn the lamp off.
Part B Repeat the entire procedure but remove the lamp. Discuss the variations
in the results.

25. Day 5: Managing the transfer of thermal energy
Divide the class into groups of 5 and ask the students to implement drama in
science and create a Talbot on the concepts learned.
The students can also create a story by each person saying a sentence based
on the prior knowledge of the concepts.
Students can work in pairs and play “Show it in action”. Student A will start
with a short sentence based on the concept. Student B will show the
action for it and say another sentence. Student A will do that action and so
on.
Talk about methods used to control the transfer of thermal energy.
Design challenge is introduced: Building a thermos using a 2L pop bottle
which will keep water above 75 degrees for two hours.

26. Societal issues that can be discussed in class
• Relate concepts to the function of steam engines.
• Dangers of rising sea levels due to global warming.
• Uses of some plastics as thermal energy conductors in the
electronics industry.
• Discuss how convection can be used to explain the process of
releasing smoke through a chimney.
• Formation of igneous rock .
• Theory behind using certain coloured clothing in countries
that receive high amounts of sunlight.
• The purpose of using certain materials by fire fighters when
fighting extreme fires.
• Annotated References.

27. Refer to the handout
• Placement of the concept within the unit.
• Place in the Curriculum.
• Advance preparations/ materials.
• Assessment (A) Evaluation (E).
• Learning styles (LS) / Multiple intelligence (MI).
• Differentiated Instruction.

28. Safety considerations:
• Show knowledge necessary to use the materials, and tools
involved in experiments.
• The skills needed to perform tasks efficiently and safely.
• Maintain a well organized and uncluttered work space.
• Follow established safety procedures.
• Identify possible safety concerns.
• Carefully follow the instructions and example of the teacher,
• Consistently show care and concern for their safety and that
of others.
• Use fire safety procedures when using candles.
• Wear safety goggles at all time.

29. Thank You
Special thank you to my mentor Roberta. Thank
you for giving me constructive feedback and
helping me set up the demonstrations.