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Gr 8 Unit 4 Revised

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					                                           Grade 8


                UNIT FOUR: INVESTIGATING THE RELATIONSHIP
                  BETWEEN ENERGY AND HEAT TRANSFER


                                         Overview
In this unit the student will be able to differentiate between potential (elastic, chemical,
gravitational) and kinetic energy. Students will analyze the transfer of potential to kinetic energy
and kinetic to potential energy and utilize the information to provide explanations for common
situations including a roller coaster ride and jumping on a trampoline. Students will be able to
identify and give examples of the common forms of energy (light, heat, chemical, electrical,
mechanical, and nuclear energy). The relationship of heat and molecular kinetic activity will be
explored by examining the results of the addition or subtraction of heat energy on the motion of
the molecules. In addition, students will be able to differentiate between heat and temperature in
terms of molecular activity. The Celsius and Kelvin temperature scales will be compared and
contrasted and absolute zero will be described. Conduction, convection, and radiation will be
compared and contrasted and an explanation of common examples of each will be made.
Students will be able to explain in simple terms how the principles of heat transfer apply to heat
engines, thermostats, and refrigerators. The objectives in this unit can be covered in an order
determined by the teacher to provide a smooth flow of information.



                              Background Information
Energy is the ability to do work. The two states of energy are kinetic and potential energy.
Potential energy is energy stored based on position or chemical composition. The amount of
potential energy associated with an object depends on its position. An apple in a tree keeps its
potential (stored) energy due to its height above the ground.

Kinetic energy is energy of motion. If the apple falls, the stored energy from its position is then
converted to kinetic energy (energy of motion). The amount of kinetic energy depends on the
mass and velocity of the moving object.

The primary forms of energy include mechanical, electrical, chemical, heat, light, sound, and
nuclear. (Sound is a form of mechanical energy)




Grade 8 Curriculum – Unit 4                                                                 Page 45
Atoms and molecules are perpetually in motion. Increased temperature means greater kinetic
energy (energy of motion), as well as molecular expansion on most substances when heated.
The temperature of absolute zero (-273 degrees C/ 0 degrees K) is the only situation in which
theoretically there is no atomic/molecular motion.

Heat, on the other hand, is not the same thing as temperature. As heat energy is added to or
taken away from a system, the temperature does not always change. There is no change in
temperature during a phase change (freezing, melting, condensing, boiling, and vaporizing).

Energy can be transformed from one type to another. Energy in the form of heat is one of the
by-products of any energy transformation. Heat energy can be transferred by means of
conduction, convection, and radiation.

Energy transformations occur in simple devices like toasters, light bulbs, motors, and hair dryers.
In a toaster, electrical energy is the input. The outputs (energy production) are heat and light
energy.




Grade 8 Curriculum – Unit 4                                                                Page 46
                                       Concept Map

                         Relationship Between Energy & Heat Transfer


Forms of         Potential Energy      Kinetic Energy        Transfer of     Transfer of
 Energy            Stored Energy        Energy in the      Thermal Energy      Energy
                   Due to Position      Form of Motion

    Light                                                                       PE  KE; KE  PE
                                                                                




                                            Molecular           Conduction
                         Elastic
                                             Motion
                                                                                    Electricity  Light
    Heat
                                            Motion of           Convection
                       Chemical
                                             Objects                            Chemical Energy 
                                                                                 Thermal Energy
  Chemical
                                                                 Radiation
                     Gravitational
                                                                                Mechanical  Sound
  Electrical

                                                                                  Chemical PE 
                                                                               Electrical  Thermal
 Mechanical                                                                        Energy  KE


                                                                                  Chemical PE 
   Nuclear
                                                                                Friction  Thermal
   Energy
                                                                                       Energy


                                                                                    Chemical PE  KE


                                                                               Electrical  Thermal
                                                                                       + Light




Grade 8 Curriculum – Unit 4                                                                    Page 47
                          Suggested Time Allotment
                                                 2 Weeks


                          Enduring Understandings
     Energy is transferred in many ways and energy changes forms, which cannot be created
      nor destroyed.


                                Essential Questions
     What vocabulary do scientists use when discussing energy?
     What is the sequence of methods that can be used in scientific research or in other
      information management processes?
     What are the two states of energy?
     What are the primary forms of energy?
     What is the definition of energy?
     What is the difference between heat and temperature?
     What are three ways heat energy can be transferred?
     What are some examples of devices that transform energy from one form to another?
     What is the energy input and output in each device?




               Instructional Objectives and Enablers
8.4.1 Define key terminology associated with unit

8.4.2 Differentiate between potential (elastic, chemical, gravitational) and kinetic energy

8.4.3 Analyze and describe the transfer of energy (potential to kinetic and vice versa) that take
      place in everyday life including a roller coaster ride and a person using a trampoline

8.4.4 Using diagrams or concrete examples to compare relative amounts of potential kinetic
      energy

8.4.5 Identify and give examples of common forms of energy (light, heat, chemical, electrical,
      mechanical, and nuclear energy)

8.4.6 Relate heat and molecular kinetic activity by illustrating and explaining the results of
      addition or subtraction of heat energy on the motion of molecules

8.4.7 Differentiate between heat and temperature in terms of molecular activity



Grade 8 Curriculum – Unit 4                                                                  Page 48
8.4.8 Compare and contrast Celsius and Kelvin temperature scales and describe absolute zero

8.4.9 Analyze a time/temperature graph of a phase change experiment to determine the
      temperature at which the phase change occurs (freezing point, melting point, or boiling
      point)

8.4.10 Compare and contrast conduction, convection, and radiation and provide and explain
       common examples of each

8.4.11 Explain in simple terms how the principles of heat transfer applies to heat engines,
       thermostats, and refrigerators

8.4.12 Design an investigation or create a diagram to illustrate energy transformations

8.4.13 Design, analyze, and critique an investigation from a testable question related to heat
       transfer (refer to standard one for specific details regarding essential skills for
       experimental design)




                      Virginia Standards of Learning
PS.6   The student will investigate and understand states and forms of energy and how energy is
       transferred and transformed. Key concepts include
       a) potential and kinetic energy;
       b) mechanical, chemical, and electrical energy; and
       c) heat, light, and sound.

PS.7   The student will investigate and understand temperature scales, heat, and heat transfer.
       Key concepts include
       a) Celsius and Kelvin temperature scales and absolute zero;
       b) phase change, freezing point, melting point, boiling point, vaporization, and
          condensation;
       c) conduction, convection, and radiation; and
       d) applications of heat transfer (heat engines, thermostats, refrigeration, and heat
          pumps).




Grade 8 Curriculum – Unit 4                                                               Page 49
                              Instructional Resources
                                       Text References
                                       Physical Science
                                          Glencoe

Chapter 16, “Solids, Liquids, and Gases”
       Section 1, “Kinetic Theory” (Review) p. 488-492

       WYMSO (What You May Safely Omit)
       Section 1, “Kinetic Theory” p. 493-495
       Section 2, “Properties of Fluids” p. 497-501
       Section 3, “Behavior of Gases” p. 502 - 507


Chapter 1, “The Nature of Science”
       Section 2, “Standards of Measurement” (Review) p. 19-21

       WYMSO (What You May Safely Omit)
       Section 1, “Methods of Science” p.6-13
       Section 3, “Communicating with Graphs” p.22-26


Chapter 4, “Energy”
       Section 1, “The Nature of Energy,” p. 100-105
       Section 2, “Conservation of Energy,” p. 107-111

       WYMSO (What You May Safely Omit)
       Section 2, “Conservation of Energy” p. 112-115


Chapter 6, “Thermal Energy”
       Section 1: “Temperature and Heat,” p. 158-160
       Section 2: “Transferring Thermal Energy,” p. 164-167, 169-170
       Section 3: “Using Heat,” p. 172-178

       WYMSO (What You May Safely Omit)
       Section 1: “Specific Heat” p. 161-163
       Section 2: “Controlling Heat Flow” p. 168
       Section 3: “The Human Coolant” p. 179




Grade 8 Curriculum – Unit 4                                            Page 50
                               Ancillary Resources
Chapter Resources             Chapter 1     “The Nature of Science”
                              Chapter 4     “Energy”
                              Chapter 6     “Thermal Energy”
                              Chapter 16    “Solids, Liquids, and Gases”
                              Physical Science Examview Pro Test Bank


                                  Other Resources
Physical Science Examview Pro Test Bank
Glencoe Physical Science Puzzle Maker
Physical Science Standardized Test Practice
Physical Science Laboratory Activities Manual
Dinah Zike’s Teaching Science With Foldables
Critical Thinking/Problem Solving Resources Booklet “Energy Saving Refrigerators” p. 8


                    Choices For Evaluating The Unit
The following section contains activities that can be used to evaluate the unit. There are far more
activities listed than can be used in the allotted time for this unit. The teacher should choose
activities that will provide information on the students understanding of the objectives being
covered.
Preassessment
     5-3-1 Have students list five things they know about potential/kinetic energy, 3 questions
      they have and one application they can give using the terms.
     Bell Ringer Transparency p. 42 in Chapter 4 Chapter Resources
     Ask students to describe how the word energy is commonly used.
     Have students list as many types of energy as they can.


Formative Assessment
     Non-Fiction Writing: Have students make a list in their Science Journals of the different
      types of energy mentioned in the text. Have them list several examples of how they use
      each form of energy every day.
     Quick Non-Fiction Writing: Have students write about thermal energy and heat. See p.
      159 for details regarding the strategy of quick writes.
     Ask students to make an events chain for each of the convection currents observed in the
      lab on p. 171.
     Have students describe the energy transformation that takes place as you go up and down
      a hill.



Grade 8 Curriculum – Unit 4                                                                Page 51
Summative Assessment
     Demonstrate how the bounce height of a ball becomes lower and lower each time it
      bounces. Have students write why this happens.
     Have students research the types of heating that are common in the Tidewater area and
      why, and find information about initial cost, efficiency, and maintenance requirements of
      different systems. Work with the Language Arts teacher to facilitate this project.




                                Essential Terminology
Boiling Point                 Temperature at which the pressure of the atmosphere is equal to the
                              pressure of a liquid’s vapor, and the gas molecules can escape the
                              attractive force between the molecules.

Gravitational
Potential Energy              Energy stored by things attracted to each other by the force of gravity


Heat                          Thermal energy that flows from a warmer material to a cooler
                              material; is measured in joules

Heat engine                   Device that converts thermal energy produced by combustion into
                              mechanical energy

Heat mover                    A device, such as a refrigerator, that removes thermal energy from one
                              place and transfers it to another place and transfers it to another place
                              at a different temperature

Kinetic energy                Energy in the form of motion; depends on the mass and velocity of the
                              object

Mechanical energy             Sum of potential and kinetic energy in a system

Potential Energy              Stored energy due to position; can be converted to kinetic energy when
                              something acts to release it

Temperature                   A measure of the average kinetic energy of all particles in the object

Elastic
Potential Energy              Energy stored by things that are stretched

Chemical
Potential Energy              Energy stored in chemical bonds



Grade 8 Curriculum – Unit 4                                                                    Page 52
                    Choices For Introducing The Unit
The following section contains an activity that can be used to introduce the unit. The teacher may
substitute an alternate activity that effectively introduces the information found in the unit.

     Use the Explore Activity on p. 99 to introduce the students to the conversion of
      electricity of light and heat. Be sure to have the students complete “Observe” and
      “Assessment” sections within their lab report.




                      Choices For Teaching The Unit
This section contains choices for teaching the unit by objective. All of the objectives presented
should be covered, but it is not required that they be covered in the order presented in this
section. There are far more activities listed than can be used in the allotted time for this unit. The
teacher should choose activities that will lead the students to mastery of the objectives and
success on the evaluation component of this unit.

           Topic                         Objective                      Suggested Activities

 Terminology                  8.4.1 Define key terminology         Foldables p. 17 in Chapter 6
                              associated with unit.                 Chapter Resources
                              PS 6                                 Foldables p. 17 in Chapter 4
                                                                    Chapter Resources
                                                                   Directed Reading for Content
                                                                    Mastery “Overview of
                                                                    Energy” p. 19 in Chapter 4
                                                                    Chapter Resources
                                                                   Mini Lab:” Interpreting Data
                                                                    from a Slingshot” p. 3 in
                                                                    Chapter 4 Chapter Resource

 Potential vs. Kinetic        8.4.2 Differentiate between          Activity: “Transforming
 Energy                       potential (elastic, chemical,         Energy Using A Paper Clip”
                              gravitational) and kinetic            p. 4 in Chapter 4 Chapter
                              energy (M)                            Resource
                              PS 6




Grade 8 Curriculum – Unit 4                                                                   Page 53
           Topic                         Objective                     Suggested Activities

 Transfer of Energy           8.4.3 Analyze and describe the       Activity: “Bouncing Balls” p.
                              transfer of energy (potential to      5 in Chapter 4 Chapter
                              kinetic and vice versa) that take     Resources
                              place in everyday life including     Lab Activity: “The Energy of
                              a roller coaster ride and a           a Pendulum” p. 9-12 in
                              person using a trampoline             Chapter 4 Chapter Resources
                              PS 6                                 Enrichment Transferring
                                                                    Kinetic and Potential Energy
                                                                    p. 29 in Chapter 4 Chapter
                                                                    Resources

 Potential kinetic energy     8.4.4 Using diagrams or              Lab Activity: “The Energy of
                              concrete examples to compare          a Pendulum” p. 9-12 in
                              relative amounts of potential         Chapter 4 Chapter Resources
                              kinetic energy                       Enrichment “Transferring
                              PS 6                                  Kinetic and Potential Energy”
                                                                    p. 29 in Chapter 4 Chapter
                                                                    Resources
                                                                   “Make a Model” Activity p.
                                                                    108 - Have students work in
                                                                    groups to make a model that
                                                                    shows conversions between
                                                                    potential energy to kinetic
                                                                    energy

 Forms of Energy              8.4.5 Identify and give              Bellringer Transparency p. 43
                              examples of common forms of           in Chapter 4 Chapter
                              energy (light, heat, chemical,        Resources
                              electrical, mechanical, and
                              nuclear energy)
                              PS 6

 Heat & Molecular             8.4.6 Relate heat and                Drawing: Have students draw
 Kinetic Activity             molecular kinetic activity by         in their science journals
                              illustrating and explaining the       diagrams relating to the
                              results of addition or                molecular activity
                              subtraction of heat energy on        Explore Activity p. 157 in TE
                              the motion of molecules
                              PS 7

 Heat vs. Temperature         8.4.7 Differentiate between          Bellringer Transparency
                              heat and temperature in terms         “Crumbling Bloom” p. 44 in
                              of molecular activity                 Chapter 6 Chapter Resources
                              PS 7                                 Explore Activity p. 157 in TE


Grade 8 Curriculum – Unit 4                                                                 Page 54
           Topic                        Objective                     Suggested Activities

 Temperature Scales           8.4.8 Compare and contrast
                              Celsius and Kelvin
                              temperature scales and
                              describe absolute zero
                              PS 7

 Phase Change                 8.4.9 Analyze a                    Activity: Kinetic Theory p.29
                              time/temperature graph of a         Chapter 16 Chapter Resource
                              phase change experiment to
                              determine the temperature at
                              which the phase change occurs
                              (freezing point, melting point,
                              or boiling point)
                              PS 7

 Conduction,                  8.4.10 Compare and contrast        Activity: “Convection in
 Convection, and              conduction, convection, and         Gases and Liquids” p. 171
 Radiation                    radiation and provide and           (Students should create their
                              explain common examples of          own data table for this
                              each                                activity); or p. 5-6 in Chapter
                              PS 7                                6 Chapter Resources
                                                                 Activity: “Conduction in
                                                                  Gases” p. 7-8 in Chapter 6
                                                                  Chapter Resources
                                                                 MiniLab p. 168 in TE
                                                                  “Observing Heat Transfer by
                                                                  Radiation”; or p. 3 in Chapter
                                                                  6 Chapter Resources
                                                                 Mini Lab: “Comparing
                                                                  Thermal Conductors” p. 169
                                                                  in TE; or p. 4 in Chapter 6
                                                                  Chapter Resources

 Heat Transfer                8.4.11 Explain in simple terms  Engage students in a
                              how the principles of heat       discussion using the following
                              transfer applies to heat         prompt: “Would you prefer to
                              engines, thermostats, and        own a car with a four-cylinder,
                              refrigerators                    six-cylinder, or eight-cylinder
                              PS 7                             engine? Why?” (Use the
                                                               Cooperative Learning
                                                               Structure: Round Table to
                                                               facilitate the discussion-see p.
                                                               176 in TE)




Grade 8 Curriculum – Unit 4                                                                Page 55
           Topic                         Objective                      Suggested Activities

 Energy Transformation        8.4.12 Design an investigation       Activity: Design Your Own
                              or create a diagram to illustrate     Experiment: “Swinging
                              energy transformations                Energy” p. 116-117; or p. 7-8
                              PS 7                                  in Chapter 4 Chapter
                                                                    Resources
                                                                   Activity: “Bouncing Balls” p.
                                                                    106

 Experimental Design          8.4.13 Design, analyze, and          Activity: “Convection in
                              critique an investigation from        Gases and Liquids” p. 171
                              a testable question related to        (Students should create their
                              heat transfer (refer to standard      own data table for this
                              one for specific details              activity); or p. 5-6 in Chapter
                              regarding essential skills for        6 Chapter Resources
                              experimental design)                 Activity: “Conduction in
                              PS 7                                  Gases” p. 7-8 in Chapter 6
                                                                    Chapter Resources




Grade 8 Curriculum – Unit 4                                                                   Page 56

				
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