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Supplemental Worksheets Name Date Class Quick Vocabulary Lesson 1 Lesson 2 heat movement of thermal energy conduction transfer of thermal from a warmer object to a cooler object kinetic energy the energy an object or particle has because it is moving potential energy stored energy temperature represents the average kinetic energy of the particles that make up a material thermal energy sum of the kinetic energy and the potential energy of all the particles that make up an object energy between materials because of collisions between particles convection transfer of thermal energy by the movement of particles from one part of a material to another convection current movement of fluids in a cycle because of convection radiation transfer of thermal energy from one material to another by electromagnetic waves specific heat amount of thermal Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. energy it takes to increase the temperature of 1 kg of material by 1°C thermal conductor material through which thermal energy flows easily thermal contraction decrease in a material’s volume when the temperature is decreased thermal expansion increase in a material’s volume when the temperature is increased thermal insulator material through which thermal energy does not flow easily vacuum space that contains little or no matter Thermal Energy C354_003_004_CRF_QVoc_892510.ind3 3 3 3/4/10 4:08:47 PM Name Date Class Quick Vocabulary Lesson 3 heat engine machine that converts thermal energy into mechanical energy heating appliance device that converts electric energy into thermal energy refrigerator device that uses electric energy to pump thermal energy from a cooler location to a warmer location thermostat a device that regulates the temperature of a system Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 4 C354_003_004_CRF_QVoc_892510.ind4 4 Thermal Energy 3/4/10 4:08:48 PM Name Date Class Lesson Outline LESSON 1 Thermal Energy, Temperature, and Heat A. Kinetic and Potential Energy 1. Any moving object has energy. 2. The energy that is stored due to the interactions between objects or particles is called energy. 3. A moving soccer ball that has been kicked into the air has kinetic energy and energy; together they make up the energy of the ball. B. What is thermal energy? 1. The that make up matter have kinetic energy and potential energy. 2. The sum of the kinetic energy and the potential energy in the particles that make up an object is called energy. 3. Thermal energy describes the of the particles in solids, liquids, and gases. C. What is temperature? energy. 2. The average kinetic energy of the particles that make up a material is the of the material. a. A material with a(n) temperature has particles that have a greater average kinetic energy than a material with a(n) temperature. b. Particles whose average kinetic energy is large are moving at a(n) average speed than particles whose average kinetic energy is smaller. 3. Two materials can have the same temperature but different energy. For example, ice and water have the same average kinetic energy, but liquid water has thermal energy because its particles have greater potential energy than those of ice. 10 C354_008_014_CRF_L1_892510.indd 10 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 1. Scientists define temperature in terms of Thermal Energy 3/4/10 4:11:27 PM Name Date Class Lesson Outline continued 4. A(n) is used to measure temperature. a. A(n) thermometer has a liquid that and rises in a(n) tube when its temperature goes up; the liquid drops when the temperature goes down. and its level b. A(n) thermometer measures the resistance in an electronic circuit and converts this measurement into a(n) . 5. Scientists around the world use the scale. a. Water freezes at at ºC and boils ºC. b. Scientists also used the Kelvin scale; water freezes at and boils at K K. c. The lowest possible temperature for any material is called zero and is K; at this temperature the particles in a material would not be moving and would have no Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. energy. D. What is heat? 1. is the movement of thermal energy from a warmer object to a(n) 2. All objects have object. energy, but heating occurs only when energy is transferred from one object to another object. a. The rate at which heating occurs depends on the difference in between two objects; the greater the difference, the heat is transferred. b. Heating continues until all substances that are in have reached the same Thermal Energy C354_008_014_CRF_L1_892510.indd 11 . 11 3/4/10 4:11:28 PM Name Date Class Content Practice A LESSON 1 Thermal Energy, Temperature, and Heat Directions: On the line before each definition, write the letter of the term that matches it correctly. Each term is used only once. 1. the energy of motion A. thermal energy 2. the sum of the kinetic energy and the potential B. temperature energy in the particles that make up a material 3. energy stored in the interactions between objects or particles C. heat D. kinetic energy E. potential energy 4. represents the average kinetic energy of the particles that make up a material 5. the movement of thermal energy from a warmer object to a cooler object Directions: Answer each question or respond to each statement on the lines provided. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 6. Describe the relationship between the average kinetic energy and air temperature. 7. What tool is used to measure temperature? 8. List three temperature scales. Then write the boiling and freezing points of water on each scale. 9. On what does the rate at which heating occurs depend? Thermal Energy C354_008_014_CRF_L1_892510.indd 13 13 3/4/10 4:11:33 PM Name Date Class Content Practice B LESSON 1 Thermal Energy, Temperature, and Heat Directions: On each line, write the term from the word bank that correctly completes each sentence. Some terms may be used more than once or not at all. bulb closer farther fast greater kinetic lesser slow stored temperature thermal 0K 100 K 1. Anything that moves has energy. 2. Potential energy is in the interactions between objects or particles. 3. The the particles in an object are from each other, the the potential energy will be. 4. The air’s temperature depends on how the air particles move. 6. Temperature and energy of particles. energy are related, but they are not the same. 7. A thermometer is a common type of thermometer. 8. If a material is at , the particles in the material are not moving and do not have kinetic energy. 9. The rate at which heating occurs depends on the difference in between the two objects. 14 C354_008_014_CRF_L1_892510.indd 14 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 5. Temperature represents the average Thermal Energy 3/4/10 4:11:34 PM Name Date Math Skills Class LESSON 1 Convert Between Temperature Scales Temperature is a measure of the average kinetic energy on the molecules in a material. Two common temperature scales are Fahrenheit and Celsius. To convert from Fahrenheit to Celsius, use the formula: (°F - 32) °C = ________ 1.8 To convert from Celsius to Fahrenheit, use the formula: °F = (°C × 1.8) + 32 Convert 113°F to Celsius. Step 1 Identify what you want to find and the value given in the problem. You want to convert the given, 113°F, to Celsius degrees. Step 2 Substitute the values into the correct formula and solve. Work inside the parentheses first. To convert from Fahrenheit to Celsius, use the formula with Celsius degrees on the left side. (113 - 32) °C = _________ 1.8 81 °C = ___ Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 1.8 °C = 45 A temperature of 113°F is equivalent to 45°C. Practice 1. Convert 140°F to Celsius. 4. Convert 14°F to Celsius. 5. If a solution has a temperature of −20°C, 2. Convert 25°C to Fahrenheit. 3. A temperature of 100°C is equivalent to what Fahrenheit temperature? Thermal Energy C354_015_015_CRF_L1Math_892510.i15 15 what is the temperature of the solution in degrees Fahrenheit? 6. A cup of tea has a temperature of 158°F. What is the temperature of the tea in degrees Celsius? 15 3/4/10 4:12:51 PM Name Date Class Key Concept Builder LESSON 1 Thermal Energy, Temperature, and Heat Key Concept How are heat and temperature related? Directions: Use the diagram to answer each question or respond to each statement on the lines provided. 120 50 100 40 80 60 40 20 0 30 308 20 293 10 283 0 273 10 20 °F °C K Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 1. At what temperature on the Celsius scale does water freeze? 2. List room temperature on all three temperature scales. 3. Convert 180°F to Celsius. 4. Convert 75°C to Fahrenheit. 5. At what temperatures on the Fahrenheit scale does water freeze? 18 C354_017_020_CRF_L1KeyCo_892510.18 18 Thermal Energy 3/4/10 4:13:24 PM Name Date Class Lesson Quiz A LESSON 1 Thermal Energy, Temperature, and Heat Completion Directions: On each line, write the term from the word bank that correctly completes each sentence. Each term is used only once. heat kinetic energy temperature thermal energy 1. potential energy is the sum of the kinetic energy and potential energy in the particles that make up a material. 2. The energy of motion is 3. . is the energy stored in the interactions between objects or particles. 4. represents the average kinetic energy of the particles that make up a material. 5. The movement of thermal energy from a warmer object to a cooler object is called . Multiple Choice Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Directions: On the line before each question or statement, write the letter of the correct answer. 6. What happens to the temperature of water in a cup when the average kinetic energy of the water particles decreases? A. It increases. B. It decreases. C. It is not affected. 7. The particles in a melting ice cube change from solid to liquid, but their temperature does not change. As the ice melts, the particles gain A. kinetic energy and thermal energy. B. potential energy and kinetic energy. C. thermal energy and potential energy. 8. On which temperature scale does water freeze at 0°? A. Kelvin B. Celsius C. Fahrenheit Thermal Energy C354_025_026_CRF_L1Quz_892510.in25 25 25 3/4/10 4:14:36 PM Name Date Class Lesson Quiz B LESSON 1 Thermal Energy, Temperature, and Heat Completion Directions: On each line, write the term from the word bank that correctly completes each sentence. Not all terms are used. heat kinetic energy mechanical energy temperature thermal energy thermometer 1. potential energy is the sum of the kinetic energy and potential energy in the particles that make up a material. 2. The energy of motion is 3. . is the energy stored in the interactions between objects or particles. 4. represents the average kinetic energy of the particles that make up a material. 5. The movement of thermal energy from a warmer object to a cooler object is called . Multiple Choice Directions: On the line before each statement, write the letter of the correct answer. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 6. A temperature change in a substance always indicates that the A. state of the substance has changed. B. kinetic energy of the particles has changed. C. potential energy of the particles has changed. D. mechanical energy of the substance has changed. 7. As water undergoes a state change, its A. temperature and thermal energy change. B. temperature and thermal energy stay the same. C. thermal energy changes and its temperature stays the same. D. temperature changes and its thermal energy stays the same. 8. The temperature at which all particle motion stops is A. 0 Kelvin. B. 0° Celsius. C. 373 Kelvin. D. 32° Fahrenheit. 26 C354_025_026_CRF_L1Quz_892510.in26 26 Thermal Energy 3/4/10 4:14:37 PM Name Date Class Lesson Outline LESSON 2 Thermal Energy Transfers A. How is thermal energy transferred? 1. A car that has been outside on a sunny summer day will be inside. 2. Thermal energy can be from one object to another by , conduction, and convection. B. Radiation 1. is the transfer of thermal energy from one material to another by electromagnetic waves. 2. All objects, even ice cubes, radiate energy. 3. The only way for thermal energy to travel from the to Earth is through radiation; that is because radiation is the only way for thermal energy to travel through the 4. of empty space. occurs in solids, liquids, and gases. C. Conduction 1. When particles that have different kinetic energies , the kinetic energy transfer energy to particles that have kinetic energy; in this way, the average kinetic energy, or , of the materials changes. a. Because kinetic energy is being transferred, energy is also being transferred. b. is the transfer of thermal energy between materials because of collisions between the particles. c. Conduction does not stop until the energy of all the particles that are in contact is . 2. A material through which thermal energy flows easily is called a(n) not flow easily is called a(n) a. ; a material through which thermal energy does . Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. particles that have are good thermal conductors because they have that move easily, so they often collide with other particles and transfer 30 C354_028_034_CRF_L2_892510.indd 30 energy easily. Thermal Energy 3/4/10 4:15:30 PM Name Date Class Lesson Outline continued b. are good thermal insulators because their electrons do not easily, so compared with thermal conductors, few of insulators. 3. occur between electrons and atoms is the amount of thermal energy it takes to increase the temperature of 1 kg of a material by 1ºC. a. Thermal have a(n) specific heat compared with thermal low , which have a . b. Water has a(n) specific heat, which makes this liquid good for . D. Thermal Expansion and Contraction 1. An increase in a material’s volume when the temperature is increased is called ; this occurs because particles spread out as their energy increases. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 2. A decrease in a material’s volume when the temperature is decreased is called ; this occurs because closer together as their kinetic energy decreases. get E. Convection 1. The transfer of thermal energy by the movement of particles from one part of a material to another is called ; convection occurs in —liquids and gases. 2. Convection occurs, in part, because of differences in due to thermal parts of the material. , and thermal contraction in different 3. The movement of fluids up and down in a cycle because of convection is called a(n) ; these cause patterns in Earth’s climate. Thermal Energy C354_028_034_CRF_L2_892510.indd 31 31 3/4/10 4:15:31 PM Name Date Class Content Practice A LESSON 2 Thermal Energy Transfers Directions: On each line, write the term from the word bank that correctly completes each sentence. Each term is used only once. conduction convection convection current radiation specific heat thermal conduction thermal contraction thermal expansion thermal insulator 1. The movement of fluids up and down in a cycle because of convection is a 2. . is the transfer of thermal energy by the movement of particles from one part of a material to another. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 3. A is a material through which thermal energy flows easily. 4. is the amount of thermal energy it takes to increase the temperature of 1kg of a material by 1°C. 5. is the transfer of thermal energy from one material to another by electromagnetic waves. 6. A is a decrease in a material’s volume when the temperature is decreased. 7. The transfer of thermal energy between materials because of collisions between the particles is called . 8. A material through which thermal energy does not flow easily is a 9. . is an increase in a material’s volume when the temperature is increased. Thermal Energy C354_028_034_CRF_L2_892510.indd 33 33 3/4/10 4:15:38 PM Name Date Class Content Practice B LESSON 2 Thermal Energy Transfers Directions: Complete the table by writing each phrase or statement statement under the correct heading. Each phrase or statement is used only once. • A car receives thermal energy from the Sun through this. • All matter radiates thermal energy. • continues until the thermal energy of all particles in contact is equal • involves the movement of thermal energy in a liquid • occurs in fluids • the transfer of thermal energy by the movement of particles from one part of a material to another • the transfer of thermal energy between materials because of collisions between the particles • the transfer of thermal energy from one material to another by electromagnetic waves • When particles with different kinetic energies collide, the particles with higher kinetic energy transfer energy to particles with lower kinetic energy. Radiation Conduction Convection Definition: Definition: • • • • • • 34 C354_028_034_CRF_L2_892510.indd 34 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Definition: Thermal Energy 3/4/10 4:15:39 PM Name Date Key Concept Builder Class LESSON 2 Thermal Energy Transfers Key Concept In what ways can thermal energy be transferred? Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Directions: Use the diagram to answer each question or respond to each statement on the lines provided. 1. Describe the thermal energy and air near the equator. 2. Describe how radiation from the Sun heats Earth. 3. Where are most rain forests located? 4. What happens as the rising air radiates thermal energy back into space? Thermal Energy C354_036_039_CRF_L2KeyCo_892510.39 39 39 3/4/10 4:16:18 PM Name Date Class Lesson Quiz A LESSON 2 Thermal Energy Transfers Matching Directions: On the line before each definition, write the letter of the term that matches it correctly. Each term is used only once. 1. the transfer of thermal energy from one material to another by electromagnetic waves 2. the transfer of thermal energy between materials because of collisions between the particles A. conduction B. specific heat C. radiation D. convection 3. the amount of thermal energy it takes to raise the temperature of 1 kg of material by 1°C 4. the transfer of thermal energy by the movement of particles from one part of a material to another Multiple Choice Directions: On the line before each question or statement, write the letter of the correct answer. 6. In which material would thermal expansion and thermal contraction be most noticeable? A. the water in a cup B. the air in a balloon C. the metal parts of a car 7. Thermal energy from the Sun transfers to Earth by A. radiation. B. convection. C. conduction. 42 C354_042_043_CRF_L2Quz_892510.in42 42 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 5. Which material is a good thermal conductor? A. cloth B. water C. metal Thermal Energy 3/4/10 4:19:41 PM Name Date Class Lesson Quiz B LESSON 2 Thermal Energy Transfers Matching Directions: On the line before each definition, write the letter of the term that matches it correctly. Not all terms are used. 1. the transfer of thermal energy from one material to another by electromagnetic waves 2. the transfer of thermal energy between materials because of collisions between the particles 3. the amount of thermal energy it takes to raise the temperature of 1 kg of material by 1°C A. conduction B. thermal insulator C. thermal contraction D. specific heat E. radiation F. convection 4. the transfer of thermal energy by the movement of particles from one part of a material to another Short Answer Directions: Respond to each statement on the lines provided. 5. Identify one material that is a good thermal conductor and one material that is a Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. good thermal insulator. 6. Identify the type of energy transfer by which the Sun’s energy travels to Earth. 7. Relate Tell how the volume of a material is related to its temperature. Use the terms thermal expansion and thermal contraction in your response. Thermal Energy C354_042_043_CRF_L2Quz_892510.in43 43 43 3/4/10 4:19:42 PM Name Date Class Lesson Outline LESSON 3 Using Thermal Energy A. Thermal Energy Transformations 1. People can convert many forms of energy such as mechanical energy or chemical energy into energy; we can also convert thermal energy into other of energy such as mechanical energy. 2. Although energy can be transformed from one kind to another, cannot be created or destroyed. B. Heating Appliances 1. are devices that convert electric energy into thermal energy; some examples are clothes irons, and coffee makers. 2. devices such as cell phones and computers also get hot when they are in use; however, the produce does not serve a useful purpose. energy they C. Thermostats 1. A device that regulates the temperature of a system is called a(n) Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. . 2. A thermostat has a coil made of two types of metals that and contract at different rates; the coil curls and uncurls, depending on the air , to move a switch that controls a(n) . D. Refrigerators 1. A(n) is a device that uses electric energy to pump thermal energy from a cooler location to a warmer location. 2. A(n) , which is a fluid, flows through pipes that surround the compartments of the refrigerator; energy is transferred from the inside of the refrigerator to the coolant, which is why the refrigerator stays . 3. A refrigerator uses energy to move the through the refrigerator pipes. a. Starting as a liquid, the coolant passes through a(n) changes into a gas, and becomes Thermal Energy C354_045_051_CRF_L3_892510.indd 47 , . 47 3/4/10 4:27:48 PM Name Date Class Lesson Outline continued b. The coolant removes the energy from the inside of the refrigerator, so the refrigerator cools off. c. In the bottom of the refrigerator, there is a(n) that forces the coolant into a smaller space, which increases the energy of the coolant. d. The releases thermal energy into the around the refrigerator. e. This change causes the to become a liquid, and then the cooling cycle begins again. E. Heat Engines 1. A machine that converts thermal energy into mechanical energy is a(n) . 2. A(n) engine, such as those found in moving vehicles and lawn , converts thermal energy into energy. a. In a car engine, a spark ignites a fuel-air mixture, which b. In an automobile engine, only about percent of the energy of the fuel (gasoline) gets converted into energy; the rest become heat, which causes the car’s to become hot. 48 C354_045_051_CRF_L3_892510.indd 48 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. and pushes a piston down; this motion turns the crankshaft—the mechanical energy that moves the car. Thermal Energy 3/4/10 4:27:49 PM Name Date Class Content Practice A LESSON 3 Using Thermal Energy Directions: On the line before each definition, write the letter of the term that matches it correctly. Some terms will be used more than once. 1. a device that converts electric energy into thermal energy A. heating appliance B. thermostat 2. a device that is not efficient C. refrigerator 3. a device that uses electric energy to pump D. heat engine thermal energy from a cooler location to a warmer location 4. Most contain a bimetallic coil. 5. curling irons, coffee makers, and clothes irons 6. a device that regulates the temperature of a system 7. Kitchen refrigerators, toasters, coffee makers, and ovens are equipped with these. 8. transfers thermal energy from one place to Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. another 9. a machine that converts thermal energy into mechanical energy 10. Thermal energy from inside transfers to the coolant, keeping the inside cold. 11. typical automobile engine 50 C354_045_051_CRF_L3_892510.indd 50 Thermal Energy 3/4/10 4:27:53 PM Name Date Class Content Practice B LESSON 3 Using Thermal Energy Directions: On the line before each statement, write the letter of the correct answer. 1. cannot be created or destroyed. A. Heat B. Metal C. Energy 2. Coolant in a refrigerator moves A. heat B. electric C. thermal energy from one place to another. 3. Computers and cell phones get hot when you use them because some energy is always converted into A. heat; electric B. thermal; heat C. electric; thermal energy in an electronic device. 4. A Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. coil is made up of two types of metal joined together and bent into a coil. A. bimetallic B. thermostat C. heat engine 5. To something is to force it into a smaller space. A. cool B. heat C. compress 6. Internal combustion engines use A. electrical B. chemical C. mechanical energy to produce thermal energy. 7. When a heat engine converts thermal energy into mechanical energy, energy moves a vehicle. A. electrical B. chemical C. mechanical Thermal Energy C354_045_051_CRF_L3_892510.indd 51 51 3/4/10 4:27:54 PM Name Date Class Key Concept Builder LESSON 3 Using Thermal Energy Key Concept What are the energy transformations in a car engine? Directions: Use the diagram to answer each question or respond to each statement on the lines provided. Intake valve Cylinder Fuel-air mixture Piston Spark plug Exhaust valve Crankshaft Exhaust gases Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 1. How are the piston and intake valve related? 2. Explain the role of the spark plug in an internal combustion engine. 3. What would happen if the piston in the diagram failed to move up? 58 C354_055_058_CRF_L3KeyCo_892510.58 58 Thermal Energy 3/4/10 4:26:51 PM Name Date Lesson Quiz A Class LESSON 3 Using Thermal Energy Completion Directions: On each line, write the term from the word bank that correctly completes each sentence. Each term is used only once. heat engine heating appliance refrigerator thermostat 1. A device that converts electric energy into thermal energy is a . 2. A is a device that regulates the temperature of a system. 3. A is a device that uses electric energy to pump thermal energy from a cooler location to a warmer location. 4. A machine that converts thermal energy into mechanical energy is a . Multiple Choice Directions: On the line before each question, write the letter of the correct answer. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 5. Which device is a heating appliance? A. computer B. cell phone C. clothes iron 6. In which device would you find a fluid called a coolant? A. thermostat B. refrigerator C. heating appliance 7. In an internal combustion engine, what form of energy is converted to thermal energy? A. electric energy B. chemical energy C. mechanical energy Thermal Energy C354_061_062_CRF_L3Quz_892510.in61 61 61 3/4/10 4:20:49 PM Name Date Lesson Quiz B Class LESSON 3 Using Thermal Energy Short Answer Directions: Respond to each statement on the lines provided. 1. Compare and contrast a coffeemaker and a computer in terms of the thermal energy they produce. 2. Summarize the function of the coolant in a refrigerator. 3. Explain how chemical energy is transformed in an internal combustion engine. Directions: On each line, write the term from the word bank that correctly completes each sentence. Not all terms are used. coolant cylinder heat engine heating appliance refrigerator thermostat 4. A device that converts electric energy into thermal energy is a . 5. A is a device that regulates the temperature of a system. 6. A is a device that uses electric energy to pump thermal energy from a cooler location to a warmer location. 7. A machine that converts thermal energy into mechanical energy is a 62 C354_061_062_CRF_L3Quz_892510.in62 62 . Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Completion Thermal Energy 3/4/10 4:20:50 PM Lesson Outline for Teaching Lesson 1: Thermal Energy, Temperature, and Heat 1. Any moving object has kinetic energy. A. Kinetic and Potential Energy 2. The energy that is stored due to the interactions between objects is called potential energy. 3. A moving soccer ball that has been kicked into the air has kinetic energy and potential energy; together they make up the mechanical energy of the ball. B. What is thermal energy? 1. The particles that make up matter have kinetic energy and potential energy. an object is called thermal energy. 2. The sum of the kinetic energy and the potential energy in the particles that make up 3. Thermal energy describes the energy of the particles in solids, liquids, and gases. Thermal Energy c. The lowest possible temperature for any material is called absolute zero and is 0 K; at this temperature the particles in a material would not be moving and would have no kinetic energy. b. The Kelvin scale is also used by scientists; water freezes at 273 K and boils at 373 K. a. Water freezes at 0ºC and boils at 100ºC. 5. Scientists around the world use the Celsius scale. and converts this measurement into a(n) temperature. b. A(n) electronic thermometer measures the resistance in an electronic circuit a. A(n) bulb thermometer has a liquid that expands and rises in a(n) glass tube when its temperature goes up; the liquid contracts and its level drops when the temperature goes down. 4. A(n) thermometer is used to measure temperature. 3. Two materials can have the same temperature but different thermal energy. For example, ice and water have the same average kinetic energy, but liquid water has greater thermal energy because its particles have greater potential energy than those of ice. speed than particles whose average kinetic energy is smaller. b. Particles whose average kinetic energy is large are moving at a(n) greater average kinetic energy than a material with a(n) lower temperature. a. A material with a(n) high temperature has particles that have a greater average temperature of the material. 2. The average kinetic energy of the particles that make up a material is the 1. Scientists define temperature in terms of kinetic energy. C. What is temperature? T2 C354_082_087_CRF_AnsOut_892510.i82 82 3/4/10 4:34:54 PM Lesson Outline continued 1. Heat is the movement of thermal energy from a warmer object to a(n) cooler object. D. What is heat? transferred from one object to another object. 2. All objects have thermal energy, but heating occurs only when thermal energy is between two objects; the greater the difference, the faster heat is transferred. a. The rate at which heating occurs depends on the difference in temperature temperature. b. Heating continues until all substances that are in contact have reached the same Discussion Question If no object has ever reached 0 degrees Kelvin, how is the Kelvin scale useful for scientists? T3 3/4/10 4:34:55 PM Possible answer: In some fields of science, getting materials very, very cold might be useful—for example, electric current and other forms of energy travel more easily through very cold materials; when working with low temperatures, it is easier to make calculations and communicate using a scale that uses positive rather than negative numbers. Thermal Energy C354_082_087_CRF_AnsOut_892510.i83 83 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Lesson Outline for Teaching Lesson 2: Thermal Energy Transfers A. How is thermal energy transferred? 1. A car that has been outside on a sunny summer day will be hot inside. conduction, and convection. 2. Thermal energy can be transferred from one object to another by radiation, B. Radiation electromagnetic waves. 1. Radiation is the transfer of thermal energy from one material to another by 2. All objects, even ice cubes, radiate thermal energy. 3. The only way for thermal energy to travel from the Sun to Earth is through radiation; that is because radiation is the only way for thermal energy to travel through the vacuum of empty space. 4. Radiation occurs in solids, liquids, and gases. Thermal Energy b. Water has a(n) high specific heat, which makes this liquid good for cooling. conductors, which have a low specific. a. Thermal insulators have a(n) high specific heat compared with thermal of 1 kg of a material by 1ºC. 3. Specific heat is the amount of thermal energy it takes to increase the temperature b. Nonmetals are good thermal insulators because their electrons do not move easily, so compared with thermal conductors, few collisions occur between electrons and atoms of insulators. so they often collide with other particles and transfer kinetic energy easily. a. Metals are good thermal conductors because they have electrons that move easily, 2. A material through which thermal energy flows easily is called a(n) thermal conductor; a material through which thermal energy does not flow easily is called a(n) thermal insulator. c. Conduction does not stop until the thermal energy of all the particles that are in contact is equal. collisions between the particles. b. Conduction is the transfer of thermal energy between materials because of transferred. a. Because kinetic energy is being transferred, mechanical energy is also being 1. When particles that have different kinetic energies collide, the particles that have more kinetic energy transfer energy to particles that have less kinetic energy; in this way, the average kinetic energy, or temperature, of the materials changes. C. Conduction T4 C354_082_087_CRF_AnsOut_892510.i84 84 3/4/10 4:34:55 PM Lesson Outline continued D. Thermal Expansion and Contraction 1. An increase in a material’s volume when the temperature is increased is called thermal expansion; this occurs because particles spread out as their thermal energy increases. 2. A decrease in a material’s volume when the temperature is decreased is called thermal contraction; this occurs because particles get closer together as their kinetic energy decreases. E. Convection 1. The transfer of thermal energy by the movement of particles from one part of a material to another is called convection; convection occurs in fluids—liquids and gases. expansion and thermal contraction in different parts of the material. 2. Convection occurs, in part, because of differences in density, due to thermal a(n) convection current; these currents cause patterns in Earth’s climate. 3. The movement of fluids up and down in a cycle because of convection is called Discussion Question Compare and contrast the three different ways that thermal energy is transferred. 3/4/10 4:34:56 PM T5 Radiation is the transfer of thermal energy as electromagnetic radiation, which can occur through all three states of matter, as well as through a vacuum; radiation is the only way thermal energy can be transferred that does not necessarily involve matter. Conduction is the transfer of thermal energy through direct contact between particles; it occurs in all three states of matter, but occurs most efficiently in specific solids called thermal conductors. Convection is the transfer of thermal energy due to movement of particles from one part of a particular material to another; convection occurs in fluids, including air and liquids, due to differences in the density of the material. Thermal Energy C354_082_087_CRF_AnsOut_892510.i85 85 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Lesson Outline for Teaching Lesson 3: Using Thermal Energy Lesson Outline continued mowers, converts thermal energy into mechanical energy. 2. A(n) internal combustion engine, such as those found in moving vehicles and lawn Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. a. In a car engine, a spark ignites a fuel-air mixture, which expands and pushes a piston down; this motion turns the crankshaft—the mechanical energy that moves the car. A. Thermal Energy Transformations 1. People can convert many forms of energy such as mechanical energy or chemical energy into thermal energy; we can also convert thermal energy into other forms of energy such as mechanical energy. b. In an automobile engine, only about 20 percent of the chemical energy of the fuel (gasoline) gets converted into mechanical energy; the rest become heat, which causes the car’s engine to become hot. C354_082_087_CRF_AnsOut_892510.i87 87 Thermal Energy 3/4/10 4:34:57 PM T7 Despite the name, a cooler does not actually cool an area; it is not a refrigerator because it doesn’t use electric energy at all; instead of cooling an area, a cooler insulates a compartment, slowing the transfer of thermal energy from the warm area outside the cooler to the compartment that has cool materials inside it. Is a plastic cooler an example of a refrigerator? Explain your answer. Discussion Question 2. Although energy can be transformed from one kind to another, energy cannot be created or destroyed. B. Heating Appliances some examples are clothes irons, and coffee makers. 1. Heating appliances are devices that convert electric energy into thermal energy; use; however, the thermal energy they produce does not serve a useful purpose. 2. Electronic devices such as cell phones and computers also get hot when they are in 1. A device that regulates the temperature of a system is called a(n) thermostat. C. Thermostats 2. A thermostat has a bimetallic coil made of two types of metals that expand and contract at different rates; the coil curls and uncurls, depending on the air temperature, to move a switch that controls a(n) furnace. D. Refrigerators a cooler location to a warmer location. 1. A(n) refrigerator is a device that uses electric energy to pump thermal energy from 2. A(n) coolant, which is a fluid, flows through pipes that surround the compartments of the refrigerator; thermal energy is transferred from the inside of the refrigerator to the coolant, which is why the refrigerator stays cold. 3. A refrigerator uses electrical energy to move the coolant through the refrigerator pipes. and becomes cooler. a. Starting as a liquid, the coolant passes through a(n) valve, changes into a gas, the refrigerator cools off. b. The coolant removes the thermal energy from the inside of the refrigerator, so into a smaller space, which increases the thermal energy of the coolant. c. In the bottom of the refrigerator, there is a(n) compressor that forces the coolant d. The coolant releases thermal energy into the air around the refrigerator. begins again. e. This change causes the coolant to become a liquid, and then the cooling cycle Thermal Energy 1. A machine that converts thermal energy into mechanical energy is a(n) heat engine. E. Heat Engines C354_082_087_CRF_AnsOut_892510.i86 86 T6 3/4/10 4:34:56 PM Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.