Third Grade: Unit 1-Heat. heat molecules insulator conduction

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1 Third Grade: Unit 1-Heat heat molecules insulator conduction Background Information for the Teacher: The Sun is the major source of heat energy on Earth. The sun s rays travel through space, striking everything on Earth exposed to them. The sunlight that strikes the Earth s surface is converted to heat energy. Heat from the Sun is transferred by radiation. The Sun s heat warms soil, sand, water, and rock. Soil absorbs heat energy faster than water, but also releases it more quickly. Water warms and cools very slowly. Surfaces vary in how much of the Sun s heat energy they reflect or absorb, partly due to color. The more of the heat energy that is absorbed, the warmer the temperature of the surface will become. A white surface appears white because it reflects most of the Sun s light and heat back into space. Because of this reflection of heat and light, white surfaces are cooler than most other colors. A black surface appears black because it absorbs more heat and light instead of reflecting it as white does. Since black surfaces absorb more heat they become warmer. The texture of the surface also determines how much heat energy will be absorbed or reflected. If the surface is shiny it will reflect more of the Sun s heat energy back into space. A dull surface may absorb more of the heat energy. Thin surfaces absorb heat faster than thick surfaces and rough surfaces absorb more heat than smooth surfaces. If two things are touching each other, heat will flow from the hotter object to the colder object, unless they are the same temperature. The molecules of the hotter material will slow down as their heat energy is transferred to the colder object. As the heat energy transfers to the molecules of the colder object, the molecules will speed up, causing the temperature of the colder object to increase. This transfer will continue until the molecules in both objects are all moving at the same speed. This will cause the two objects to have the same temperature. For instance, if you put an ice cube in your mouth, your mouth will get colder, and the ice cube will warm up and melt. This is because the warmer molecules from your mouth transfer to the ice cube, causing it to heat up and melt. Your mouth gets cold because it is transferring its heat into the ice cube. When molecules are cold, they are very close together and are not moving very much. They are similar to a crowd of people standing still. But as molecules heat up and move faster, they begin to vibrate, bumping into each other. As they vibrate harder and harder, they begin to bounce off each other, and then they bump into other molecules. This bumping pushes them farther apart from each other. Because of this, hot things have more space between the molecules than cold things, and the same number of molecules take up more

2 space when they are hot. Hot objects tend to expand while cold objects contract in size. Heat is measured by temperature. Conduction is the flow of heat through a material from areas of greater heat energy to areas of less heat energy. If you hold a metal spoon in your hand the heat from your almost 100 degree hand transfers to the cooler metal of the spoon. In a short time, the spoon will absorb some of the heat from your hand, making it feel warmer. Heat causes the molecules in matter to vibrate rapidly, bumping into nearby molecules and passing the heat energy on to them. The heat energy travels from molecule to molecule causing the heat energy to move from areas of more heat to areas of less heat. The conduction of heat energy slows down as it travels farther from the source of the heat. Metal is a good conductor of heat. Poor conductors like wood, plastic, and cloth do not allow for the easy movement of heat energy. They are called insulators. Insulation is any material that is used to slow down or reduce the flow of heat energy. The substances used to produce insulating materials are poor conductors of heat, thus not allowing the heat to transfer to other objects or into the air. Materials like fiberglass, rock wool, styrofoam, and wool are widely used to make insulators. We use insulated materials every day; in coolers and foam cups, freezers, our homes, air conditioning units, and winter clothing. Heat: a form of energy that is transferred by a difference in temperature Molecule: the smallest particle of a substance that retains all the properties of the substance and is composed of one or more atoms Insulator: any material that is used to slow down or reduce the flow of heat energy. Conduction: the flow of heat through a material from areas of greater heat energy to areas of less heat energy.

3 Activity 1: Read the short photo diary of the Innuit boy, Latti. Hi. I am Latti. I am an Inuit and I live with my family in the Arctic. Because we are closer to the North Pole, it is very cold here most of the year. This is my caribou, Rustik. Caribou are very useful to us. We use caribou skins for clothing, summer tents, and blankets. My jacket and leggings are made of caribou hide. You may call caribou reindeer, because they are the same animal. This is my teacher. We are walking across the village on our way back from recess. We play stickball and run races but we have to stomp down the snow first. It is a little difficult to run in all of the thick clothing we have to wear, but the layers insulate us from the cold wind outside. See the ice hut in the background? That s where we store our meat, frozen hides, and cooking oil. We get most of these things from marine mammals like walruses, narwhals, and beluga whales. Everyone uses the ice hut. It s like a grocery store!

4 This is my house. It is made of sod and hides. It is our winter house. The layers of sod help to keep the warm air inside. In the summer we live in tents. The ice hut in the front is used for extra warmth and for storage. This is my father. He is going on a hunting trip. The sled dogs are fast and can travel many miles each day. They have thick fur to insulate them from the cold. They sleep all together in a pile to share body heat during the night. After the hunt, the strong dogs will haul back the meat, hides, weapons, and tools needed to build the ice huts that the men will sleep in as they travel. Notice we don t have many trees. We hunt marine mammals to provide us with the oil we burn for heat and light, the bones we use to make tools, and the meat we eat. Have you ever had a walrus sandwich? Yummy! I am curious to learn about your life. What would it be like if you could visit me? Please write me a story describing what might happen if you came to visit me for a couple of weeks. Tell me how you would feel and what would be different for you. I look forward to reading it. It will be an exciting story to share with my friends!

5 Ask the students to look at each picture carefully. Describe the details that tell them about Latti s life and environment. Ask them to use their five senses to explain how objects and the weather might feel, smell, and look. Consider the sounds that might be heard. As the students are discussing the pictures, record their dictation, making sure the students can clearly see what you are writing. Try to copy what they say word for word; do not rephrase anything at this time After the discussion has covered each picture fully, read the text you wrote for the students. As you read, model fluency and help them make connections between what is said and what is written by pointing to key words. Answer any questions that they may have and clarify anything that is confusing or could be restated more clearly. Begin to develop the students discussion into the story format requested by Latti. Have the students imagine what they would do and how they would feel if they arrived in Latti s village for a visit. Allow the students to create the story, prompting them with sequence and possible events that include as many of the vocabulary words as possible. Once the story is completed, read it to the students in entirety. After modeling fluency, have them read the text orally and silently. This will help them develop fluency. Once the students are familiar with the story, begin to focus on the vocabulary words and their use in context in the story.

6 Activity 2: Student Handout 1: Have students complete the Knowledge Rating Scale. Word sun heat molecule insulation ice Know it Well Give a Definition and Examples Knowledge Rating Scale Have Seen It/Heard It Here s what I know No clue Take a Guess After the students have worked independently on the Knowledge Rating Scale, discuss each word to check for previous experience with the words and concepts. Generate discussion that allows the students to come up with a child-friendly definition for each word. Put the definitions on sentence strips where students can refer to them throughout the unit. Discuss how the words may have been used in the story and include them in appropriate sentences to enhance the meaning.

7 Activity 3: Student Handout 2: What are your ideas about heat? Have students complete the Idea Chart below. Encourage them to give their ideas on each statement to help explain their True/False answer. Allow students to give examples if desired. Statement True False My Ideas Snow has heat. Heat makes molecules move faster. A large block of ice has more heat than a burning match. Anything with molecules has heat. Conduction moves heat from one thing to another. After students have completed the Idea Chart, watch the video on the link below. Once the video is complete, revisit the Idea Charts and discuss each statement. Clear up any misconceptions and answer questions the students may have. Activity 3: Collaborative Summary Divide the students into two groups. After reading the definition of Conduction as it is listed below, ask the Group #1 students to reread the definition and summarize what it says in their own words. Record their responses. After the summary is complete, ask the Group #2 students if they have any questions or any difficulty in understanding the definition. Record their questions. Ask the Group #1 students if they can help answer or clarify the questions. Answer any remaining questions and clarify for the group if necessary. Finally, ask the Group #2 students how they think the word could be used with the other vocabulary words on the list. Discuss how the word Conduction might be used in the story from Activity 1. (eg: Cooking in a metal pot or pan over a fire or on a burner. The heat from the burner would be conducted from the burner, through the metal of the pot, into the contents of the pot. Warmth from a heating fire will conduct from

8 the flames to the clothing of the people around it to the body under the clothing.) Finalize the story and have it ready for handout on Day 5. Conduction: is the flow of heat through a material from areas of more heat energy to areas of less heat energy. 1. Students in Group #1: summarize the definition. 2. Students in Group #2: ask questions on unclear material. 3. Students in Group #1: clarify the unclear material. 4. Students in Group #2: make an illustration to show conduction. Activity 5: Vocabulary Diagram Student Handout 3: Have students use their own words/ideas to complete the Diagram. Draw a picture here. List some examples here. How I Use Heat in My Life Write a sentence here.. Write a definition: Heat: Conduction: Insulator:

9 Word Sun Student Handout 1 Knowledge Rating Scale Know it Well Give a Definition and Examples Have Seen It/Heard It Here s what I know No clue Take a Guess Heat Molecule Insulation Ice

10 Student Handout 2 Snow has heat. Statement True False My Ideas Heat makes molecules move faster. A large block of ice has more heat than a burning match. Anything with molecules has heat. Conduction moves heat from one thing to another.

11 Student Handout 3 Draw a picture here. List examples here. Write a sentence. How I Use Heat in My Life Write a definition: Heat: Conduction: Insulator: