HEAT (PART 1) 8 TH GRADE CHAPTER 21 SECTION 2. DO NOW…CONVERSION PRACTICE The temperature of the...
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Transcript of HEAT (PART 1) 8 TH GRADE CHAPTER 21 SECTION 2. DO NOW…CONVERSION PRACTICE The temperature of the...
![Page 1: HEAT (PART 1) 8 TH GRADE CHAPTER 21 SECTION 2. DO NOW…CONVERSION PRACTICE The temperature of the science lab is 70 F. What is this temperature in Celsius?](https://reader035.fdocuments.in/reader035/viewer/2022062801/56649e715503460f94b6ed9c/html5/thumbnails/1.jpg)
HEAT (PART 1)8TH GRADE
CHAPTER 21 SECTION 2
![Page 2: HEAT (PART 1) 8 TH GRADE CHAPTER 21 SECTION 2. DO NOW…CONVERSION PRACTICE The temperature of the science lab is 70 F. What is this temperature in Celsius?](https://reader035.fdocuments.in/reader035/viewer/2022062801/56649e715503460f94b6ed9c/html5/thumbnails/2.jpg)
DO NOW…CONVERSION PRACTICE
•The temperature of the science lab is 70 F. What is this temperature in Celsius?
•The temperature outside is 25 C. What is this temperature in Fahrenheit?
![Page 3: HEAT (PART 1) 8 TH GRADE CHAPTER 21 SECTION 2. DO NOW…CONVERSION PRACTICE The temperature of the science lab is 70 F. What is this temperature in Celsius?](https://reader035.fdocuments.in/reader035/viewer/2022062801/56649e715503460f94b6ed9c/html5/thumbnails/3.jpg)
THERMAL ENERGY (FROM YESTERDAY)
Potential Energy
•1) Molecules in a material exert attractive forces on each other
•Ex: Gravity exerts an attractive force on a ball.
•2) Molecules in a material have potential energy
•Ex: A ball above the ground has potential energy.
•3) As molecules move closer together or farther apart, potential energy changes
•Ex: As a ball moves closer to or farther from Earth’s surface, its potential energy changes.
![Page 4: HEAT (PART 1) 8 TH GRADE CHAPTER 21 SECTION 2. DO NOW…CONVERSION PRACTICE The temperature of the science lab is 70 F. What is this temperature in Celsius?](https://reader035.fdocuments.in/reader035/viewer/2022062801/56649e715503460f94b6ed9c/html5/thumbnails/4.jpg)
OBJECTIVES
Students will…
•Explain the difference between thermal energy and heat
•Describe 3 ways thermal energy is transferred
![Page 5: HEAT (PART 1) 8 TH GRADE CHAPTER 21 SECTION 2. DO NOW…CONVERSION PRACTICE The temperature of the science lab is 70 F. What is this temperature in Celsius?](https://reader035.fdocuments.in/reader035/viewer/2022062801/56649e715503460f94b6ed9c/html5/thumbnails/5.jpg)
HEAT AND THERMAL ENERGY
• Heat is the transfer of thermal energy from one object to another when objects are at different temperatures.
• The amount of thermal energy that is transferred when 2 objects are brought into contact depends on the difference in temperature between objects.
20 degree
s
100 degree
s
60 degree
s
60 degree
s
![Page 6: HEAT (PART 1) 8 TH GRADE CHAPTER 21 SECTION 2. DO NOW…CONVERSION PRACTICE The temperature of the science lab is 70 F. What is this temperature in Celsius?](https://reader035.fdocuments.in/reader035/viewer/2022062801/56649e715503460f94b6ed9c/html5/thumbnails/6.jpg)
CONDUCTION, RADIATION AND CONVECTION
• Transfer of thermal energy by direct contact by collisions between particlesConducti
on
• Transfer of energy by electromagnetic waves
Radiation
• Transfer of thermal energy by the movement of particles in a gas or liquid
Convection
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CLASSIFYING TYPES OF ENERGY TRANSFER
•Complete each sentence using radiation, convection or conduction
•1) The sun’s rays heat sand particles by ____________.
•2) Cool air pushes in to replace warm, air flow by natural _____.
•3) Body heat is transferred in to the air by _______.
•4) Heat from the sun warms iced tea by __________.
•5) A fan pushes air molecules by forced__________.
![Page 8: HEAT (PART 1) 8 TH GRADE CHAPTER 21 SECTION 2. DO NOW…CONVERSION PRACTICE The temperature of the science lab is 70 F. What is this temperature in Celsius?](https://reader035.fdocuments.in/reader035/viewer/2022062801/56649e715503460f94b6ed9c/html5/thumbnails/8.jpg)
MINI LAB: COMPARING RATES OF MELTING
•Purpose: Observe the effect of ice water on melting ice.
•Lab procedures/directions
•Complete lab worksheet.
•Questions?
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FOR NEXT TIME….
•Read pgs. 616-617
•Define convection, conductor, specific heat and thermal pollution on index cards.
•Test signed by Thursday.
![Page 10: HEAT (PART 1) 8 TH GRADE CHAPTER 21 SECTION 2. DO NOW…CONVERSION PRACTICE The temperature of the science lab is 70 F. What is this temperature in Celsius?](https://reader035.fdocuments.in/reader035/viewer/2022062801/56649e715503460f94b6ed9c/html5/thumbnails/10.jpg)
HEAT (PART 2)8TH GRADE
CHAPTER 21 SECTION 2
MINI LAB
![Page 12: HEAT (PART 1) 8 TH GRADE CHAPTER 21 SECTION 2. DO NOW…CONVERSION PRACTICE The temperature of the science lab is 70 F. What is this temperature in Celsius?](https://reader035.fdocuments.in/reader035/viewer/2022062801/56649e715503460f94b6ed9c/html5/thumbnails/12.jpg)
OBJECTIVES
Students will…
•Identify materials as insulators or conductors
•Complete mini-lab to observe convection
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THERMAL CONDUCTORS VS. THERMAL INSULATORS
Thermal Conductors
- Conducts heat easily
-gold and copperMaterial contains
loosely held electrons
Thermal Insulators- Does not
conduct heat easily
-materials do not contain loosely held electrons
Depend on how strongly atoms hold electrons
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HEAT ABSORPTION
•Specific Heat- is the amount of thermal energy needed to raise the temperature of 1kg of the substance by 1 degree C.
•More thermal energy is needed to change the temperature of a material with a high specific heat than one with a low specific heat.
•Ex: sand on a beach has lower specific heat than ocean water
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THERMAL POLLUTION
•Thermal pollution- increase in the temperature of a body of water caused by adding warmer water.
•Effects: organisms need more oxygen and warmer water has less dissolved oxygen=organisms die due to low oxygen. Also organisms are more sensitive to chemical pollutants, parasites and disease.
•Reducing: Cooling warm water produced by factories, power plants and run off.
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MINI LAB: OBSERVING CONVECTION
Purpose: Observe convection process
•Lab procedures/directions
•Safety precautions (esp. wearing goggles during experiment!)
•Complete lab worksheet
•Proper clean up
•Questions?
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FOR NEXT TIME…
Khan Academy Videos
•Converting F to C
•Comparing F and C
•Each lab group needs to bring a pair of oven mitts or pot holders.