Name Lesson 1 Summary Use with pp. 359–361 Lesson 1: What is energy? Vocabulary potential energy stored energy that has the ability to change in order to do work or cause a change kinetic energy the energy of motion Energy You also release potential energy when Energy is the ability to do work or cause you use batteries. The stored energy in fuels, change. Work is done when a force makes batteries, and food is chemical energy. an object move. You have learned about A skier at the top of a hill has another the Sun’s energy. Earth gets heat energy kind of potential energy. This kind of and light energy from the Sun. The Sun’s potential energy comes from height or heat energy warms the Earth. The Sun’s position. Picture a swing at its highest light energy makes plants grow. The Sun’s point. This swing also has potential energy. energy also causes winds to blow. It causes Energy of Motion water to move through a cycle too. Potential energy can also turn into You use energy from the Sun every day. kinetic energy. Kinetic energy is the You also use many other forms of energy. energy of motion. For example, stored Electrical energy runs many things in your energy in gasoline can change into kinetic kitchen. Chemical energy runs the engine energy. This energy allows a car to move. A of a car. The mechanical energy of the skier standing at the top of a hill pushes off car’s motion moves you from one place to in order to move. This is when the skier’s another. stored potential energy changes to kinetic Stored Energy energy. The force of gravity then pulls the Think about a person on skis. The skier skier down the hill. uses energy to ski. The skier’s body stores Many kinds of energy can be renewed. this energy. Stored energy is a kind of The skier can get more energy by eating potential energy. Potential energy can food. The skier can also climb the hill change into a different kind of energy in again. Other kinds of energy cannot easily order to do work or cause change. be renewed. For example, gasoline, natural Fuels are sources of energy. Oil, coal, gas, coal, and other fossil fuels are not natural gas, and gasoline are fuels. The renewable. energy stored in these fuels comes from © Pearson Education, Inc. 3 sunlight. Long ago, plants used energy from the Sun to make food. Then the plants died. They turned to a kind of fossil that we now use as fuel. We release the potential energy in the fuels when we burn them. 82 Chapter 13, Lesson 1 Summary Quick Study
Name Lesson 1 Checkpoint Use with pp. 359–361 Lesson 1 Checkpoint 1. What are two forms of energy that Earth gets from the Sun? 2. What are two kinds of potential energy? 3. Give two examples of potential energy and kinetic energy that you see every day. 4. Main Idea and Details Use a graphic organizer. What is the main idea of the first paragraph under “Energy of Motion”? What details support it? © Pearson Education, Inc. 3 Quick Study Chapter 13, Lesson 1 Checkpoint 83
Name Lesson 2 Summary Use with pp. 362–365 Lesson 2: How does energy change form? Changing Forms of Energy Ways That Energy Travels Energy can change from one form into Energy can travel from one place to another. For example, living things store another. A moving object carries energy. potential energy as chemical energy. For example, you can feel the energy a Chemical energy in your body changes to moving ball is carrying when you catch it. mechanical energy and heat energy as you Energy can also travel as waves. Look at move. Potential energy can also change the rope on page 365 in your textbook. A into the forms listed below: person is moving the rope from side to side. • Chemical energy This energy holds This makes energy move along the rope particles of matter together. Food and in waves. Light energy and kinetic energy fuel contain chemical energy. move in waves. • Mechanical energy This is the energy Energy in water moves in waves. These of moving objects. Moving parts in waves can be small. Waves caused by machines use kinetic energy. Your body hurricanes can be huge. The size of a wave also uses mechanical energy when it depends on how much energy it carries. moves. Waves lose strength as they move away from their source. • Electrical energy This energy can pass through wires made of special Parts of a Wave metal. We use this energy to power You can measure the amount of energy many machines. that a wave carries. One way you can do • Light energy We see the Sun’s energy this is by measuring the width of a wave. as light. Plants use light energy to make The width is the distance between the food. bottom of the wave to the top of the wave. • Thermal energy This form of energy The bottom of a wave is called a trough. makes particles move faster. We feel The top of a wave is called a crest. Wide thermal energy as heat. waves have lots of energy. Thin waves have less energy. Using Energy You can also measure the length of an When you turn on a light, this helps energy wave. The length of a wave is the change electrical energy to light energy. distance from the top of one crest to the top The light bulb will get hot. This is because of the next crest. Shorter waves have lots of some of the electrical energy changes energy. Longer waves have less energy. to heat energy. Energy cannot change completely from one form to another. Some energy is given off as heat. People also use machines to change © Pearson Education, Inc. 3 forms of energy. An electric toothbrush can change chemical energy into electrical energy. It changes electrical energy to mechanical energy when the toothbrush is turned on. 84 Chapter 13, Lesson 2 Summary Quick Study
Name Lesson 2 Checkpoint Use with pp. 362–365 Lesson 2 Checkpoint 1. What form of energy do living things change into mechanical energy and thermal energy? 2. Name two types of energy that travel in waves. 3. What happens to energy as it travels away from the source? 4. Main Idea and Details Read the first paragraph under “Parts of a Wave.” Use a graphic organizer. What is the main idea? What are the supporting details? © Pearson Education, Inc. 3 Quick Study Chapter 13, Lesson 2 Checkpoint 85
Name Lesson 3 Summary Use with pp. 366–369 Lesson 3: What is heat energy? Vocabulary thermal energy the total energy of all the particles in matter; also called heat energy Heat Energy Effects of Heat on Matter All matter is made of very small Heat energy changes matter. Energy particles. These particles are always causes matter to be in a solid, liquid, or gas moving. Particles need energy to move. state. Think about a cup of liquid water. Thermal energy is the energy of The water turns to ice if the temperature is moving particles. at or below 0°C (32°F). The Sun is the main source of heat on What happens when you add heat to Earth. Sunlight feels warm on your skin. ice? Ice starts to melt. Ice becomes a liquid The sunlight makes your skin’s particles as the temperature warms. move faster. This makes you feel warmer. You can measure the effect of heat on We feel thermal energy as heat. matter. You can watch how much time Thermal energy moves as heat. It moves it takes for matter to change from solid from a warmer object to a cooler object. to liquid. This change will happen faster Put a spoon in very hot water. Heat moves when there is greater heat energy. from the hot water through the cooler Water evaporates when enough heat spoon. Soon, the spoon will feel warm. is added to it. Water changes into a gas The water and the spoon will reach the called water vapor. You cannot see water same temperature. This is when the flow of vapor. Heat makes liquid water change in energy stops. another way. Heat makes water boil. Water boils at a temperature of 100°C (212°F). A Sources of Heat pot of water on top of a stove will change Heat is given off when energy changes as it heats. This heat makes the water get forms. This heat can come from different bigger. Finally, the liquid water evaporates. sources. Four sources of heat are listed It changes into a gas. Hot bubbles of gas below: move to the top of the water. These bubbles • Electrical Energy The burner on an break open. They release a cloud of hot electric stove changes electrical energy water droplets. into heat. • Chemical Energy Burning wood © Pearson Education, Inc. 3 changes chemical energy into heat. • Mechanical Energy Rubbing your hands together keeps your hands warm. This is an example of using mechanical energy to produce heat. • Light Energy The light from the Sun warms Earth. This is an example of light energy changing into heat. 86 Chapter 13, Lesson 3 Summary Quick Study
Name Lesson 3 Checkpoint Use with pp. 366–369 Lesson 3 Checkpoint 1. What are four different kinds of heat sources? 2. What is the main source of heat on Earth? 3. What causes matter to be in a solid, liquid, or gas state? © Pearson Education, Inc. 3 Quick Study Chapter 13, Lesson 3 Checkpoint 87
Name Lesson 4 Summary Use with pp. 370–373 Lesson 4: What is light energy? Vocabulary reflect to have light bounce off an object and go in different directions refract to bend light absorb to take in Sources of Light All objects reflect light. This means The Sun, chemical changes, and light bounces off them. The light goes in a electricity are three sources of light energy. different direction. Some objects reflect light The Sun is the main source of light on better than others. Their surfaces are very Earth. Energy moves from the Sun to Earth. flat and smooth. A mirror reflects light. So The Sun’s energy moves as waves. We can does a lake’s surface. see some of these waves. Light is energy Some objects refract light. Refraction that we can see. makes light bend and change direction. Light can also come from chemical This can cause objects to look different. changes. Burning is a chemical change. A Look at the water drops on page 372 in candle makes light when it burns. A gas your textbook. The drops refract light from lamp makes light as it burns gas. Some the flower. The rays bend. Tiny images of animals make light too. The anglerfish can the flower form. make light. Chemical changes in the fish’s Why does light refract? Light refracts body make light. because it goes through different materials Electricity is also a source of light. at different speeds. Look at the picture of Electricity heats the wire in a light bulb. a straw in water on page 373. Light in the The wire gets so hot that it glows and gives air slows down when it goes through water. off light. Most things that give off light also The light refracts. That is why the straw give off heat. looks bent. Sometimes, refraction causes light to separate into its many colors. This The Path of Light makes a rainbow. Light travels from its source in straight Light is made of different colors. Objects lines in all directions. Light is able to travel absorb some of the light. The objects until an object stops it. Light will not bend reflect the rest of the colors. Different in order to get around an object. This is objects absorb and reflect different colors. why objects that block light’s path form A red object in sunlight reflects red light. © Pearson Education, Inc. 3 shadows. Shadows are areas behind the It absorbs all the other colors. A green objects that are not getting light. object reflects green light. A white object reflects all the colors of sunlight. A black How Light Changes object absorbs all the colors of sunlight. Some objects block all the light. Light Dark objects feel hot in the Sun. A lot of will not go through a brick. Other objects absorbed sunlight turns to heat. block only part of the light. A window does not block all the light. A glass of water does not block all the light. You can see through these objects. 88 Chapter 13, Lesson 4 Summary Quick Study
Name Lesson 4 Checkpoint Use with pp. 370–373 Lesson 4 Checkpoint 1. Name three sources of light energy. 2. What is the main source of light on Earth? 3. How does a shadow form? © Pearson Education, Inc. 3 Quick Study Chapter 13, Lesson 4 Checkpoint 89
Name Lesson 5 Summary Use with pp. 374–377 Lesson 5: What is electrical energy? Vocabulary electric charge a tiny amount of energy in the particles of matter electric current the movement of an electric charge from one place to another electric circuit the path that a controlled, electric current flows through Electric Charges Electric Currents and Circuits All matter is made of small particles. Electric current is the movement These particles have electric charges. An of electrical energy. Lightning is an electric charge is a small amount of uncontrolled electric current. Controlled energy. Particles have positive and negative electric current travels in a planned way charges. Particles balance each other out through wires. when they have the same number of An electric circuit controls the path that positive and negative charges. This matter electricity takes. The path must be unbroken has no charge. When matter has more for electricity to flow through it. Look at the negative charges than positive charges, this simple electrical circuit on page 376 in your matter has a negative charge. Other matter textbook. The circuit is unbroken when the has more positive charges than negative switch is on. This lets electric current flow charges. This matter has a positive charge. from the negative to the positive part of the Matter with a negative charge is attracted battery. On its way, it flows through a bulb. to matter with a positive charge. The A wire in the bulb gets hot and glows. This negative charge moves toward the matter electrical energy changes to heat and light with the positive charge. This happens energy. The current stops flowing when you when you touch someone and get a shock. turn the switch off. Negative charges jump between you and We use electricity every day. So we try to the other person. Electric charges also create change sources of energy into electricity. lightning. Light is given off when negative We change energy from running water into electric charges move in clouds. electricity and turn the heat of burning Electric charges can make objects stick coal into electricity. together. This happens when negative and Electricity changes its form when it gets positive charges are attracted to each other. to your house. Electricity can change into: Rub a balloon on your hair. The balloon • Light Electricity in light bulbs changes © Pearson Education, Inc. 3 will pick up negative charges from your to light. hair. The balloon will stick to paper with a • Heat Electricity moves through coils in positive charge. heaters and changes into heat. Objects can push away from each other • Sound Electricity moves around a when their charges are the same. Rub two magnet in a radio. The magnet changes balloons together. They will both have electric energy into sound. negative charges. The balloons will push apart. • Magnetic Force Electricity moves around a huge magnet and makes it very powerful. This magnet can lift cars. 90 Chapter 13, Lesson 5 Summary Quick Study
Name Lesson 5 Checkpoint Use with pp. 374–377 Lesson 5 Checkpoint 1. What causes lightning? 2. What is the difference between a controlled and an uncontrolled electric current? Give an example of each. 3. What happens when an electric circuit is open? 4. Main Idea and Details Describe the path of electricity through a simple electric circuit. © Pearson Education, Inc. 3 Quick Study Chapter 13, Lesson 5 Checkpoint 91