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1 Ryan Palmer 3-9-05 EDTEP 587 Unit Plan Transfer of Thermal Energy: Radiation, Conduction, & Convection 8th Grade Earth Science 2 Subject Area Description This unit is a sub-unit in the context of a larger unit on energy. Prior to this unit students will have learned about mass, volume, and density, as well as touched on buoyancy. Those students who had science at my junior high in 7th grade (this excludes new students and students who did not take science in 7th grade) will have talked about solar energy hitting the earth unevenly, as well as mentioning the existence of convection cells in the earth’s atmosphere (though the students received no terminology or understanding of the process behind the cells). The students will also have had experience in the inquiry process, though only to the extent of crafting their own hypothesises and then running the prescribed experimental procedure. They will have done at least two labs prior to this sub-unit, and will be familiar with the lab protocol specific to my CT’s classroom. The students at this junior high school are mostly in the middle economic class. The half of the 8th grade that my CT has contains all the learning center students (those who have IEPs), but none of the students with 504 plans. Supposedly our half of the 8th grade also has some of the brightest students to help balance out the learning center students. Frequently para-educators will sit in on a class and assist students who need extra help and guidance. Essential Questions The essential question and its subsequent sub-questions are designed around a demonstration I will do for the students in the beginning of the sub-unit. I will build a fire, either in the classroom or just outside, and have the students make observations related to the main question. Each sub-question gets at each of the three different types of 3 thermal energy transfer: radiation, conduction, and convection. The example of the fire will contextualize the entire sub-unit and will be continually referenced as each new concept is introduced. The fire will also be used to model scientific modeling for the students. By demonstrating the fire in front of each class it gives the students a common experience to draw on and a context to put their new understanding of heat transfer into. How does a fire keep us warm? -How does a fire heat someone near it? -How does a fire heat the ground around it? -How does a fire heat the air around it (and eventually a room; e.g. woodstove)? How does a thermos maintain its temperature? How does night vision work? How can heat move a liquid? Learning Goals & Related Objectives 1. Students will understand that heat and temperature are connected to molecular motion 1.1. Students will understand the relationship between molecular movement and temperature 1.2. Students will provide evidence that temperature is the measure of the motion of molecules 2. Students will understand how various factors affect energy transfers and that energy can be transferred from one form of energy to another (EALR/GLE 1.2.2) 2.1. Students will understand that heat energy can be passed by things touching each other (conduction) 4 2.2. Students will apply their understanding of conduction needing contact between substances to transfer heat energy 2.3. Students will explain how radiant heat is transferred (does not need a medium) 2.4. Students will connect density and buoyancy to the creation of a convection cell 3. Students will analyze how models are used to investigate objects, events, systems, and processes (EALR/GLE 2.1.4) 3.1. Students will model their understanding of convection in a new system 3.2. Students will understand that scientific phenomena can be modeled in many different ways (writing, pictures/drawing, physical models, etc.) 3.3. Students will support a revised model of insulators 3.4. Students will construct an experimental procedure based on a model given to them 3.5. Students will analyze experimental designs based on a model and determine the factors that are important for insulators 4. Students will understand the fluid nature of scientific ideas 4.1. Students will understand how heat is given off in different ways in a fire 4.2. Students will understand that multiple scientific concepts can contribute to the same phenomenon 5 Day 1: Introduction to Heat Transfer—Let’s build a fire! (50 minutes) 1. What students are doing Students will see a demonstration of a fire built in the classroom. They will observe how the fire gives off heat, making informal notes for their science notebooks. This will include how hot, where they feel the heat, what gets hot, and anything else they observe about the fire. Students will then break into small groups and discuss what they observed and why they think they may have seen some of their observations. Together the small groups will compile a list of observations, as well as questions that may have come up during their observations and/or discussions. Finally students will share these observations and questions with the whole class and compile a class list of observations and questions 2. Objectives 4.1 Students will understand how heat is given off in different ways in a fire 3. Reasons for content and The fire demonstration forms a common reference point we will instructional strategy continue to return to through out the unit. It gives the students a common experience from which they can all draw upon in their understanding of thermal energy transfer. Beginning the unit with eliciting student ideas allows the teacher to know where the students are with their understandings and what they bring into the classroom. It also allows the students to begin the unit with the freedom to express what they see and know without it being corrected or redirected. This gives them a greater feeling of mastery of the subject matter Combining this with the beginnings of guided exploration gives the students a chance to begin to form their own scientific understandings of how heat is transferred. It also pushes them to think about their observations in a connected way. Having the students compose questions of things they don’t understand from their fire observations serves two purposes. First, it allows the teacher to know the areas both of struggle and of interest for the students related to the fire and heat transfer. Second, it communicates to the students that having questions is a good and important task and reinforces their curiosity. Having the students work in small groups helps them develop interpersonal skills. It also gives them the benefit of other observations and questions they might not have seen on their own. The students can begin to synthesize ideas between observations and see how they are interrelated. 4. Evidence of understanding Students will explain their observations to their group members Students will generalize their group observations of the fire Students will craft questions based on their observations 6 5. Cultural Responsiveness This lesson allows students to report their observations of what they see with no value judgments placed on those observations. All observations from all students of all cultural and SES backgrounds are treated as valid. The fire itself also provides an experience that all students observe and have access to in the classroom, thereby creating a common experience for the students. 6. Resources Safe place to build a fire (inside classroom or outdoors) Sand, wood, matches/lighter, kindling, fire extinguisher, container for fire/sand, lighter fluid (?), weather cover (in case it rains and is outside) Permission of school administrators White board/overhead, pens 7 Day 2: Organizing what we need to know—How do fires work? (50 minutes) 1. What students are doing Students will begin be revisiting the class list from the previous day with their questions and observations about the fire. They then will begin to construct “rules” about what they know and what they still have questions about. They’ll group similar questions and observations together and come up with a direction of knowledge they need to gain Students will then work on the idea of kinetic molecular theory (aka collision theory) as a basis for understanding what heat is They will become a human model of kinetic molecular theory, as each student represents a molecule moving based on temperature. In small groups the students will construct rules for how molecules behave based on temperature, forming their understanding of kinetic molecular theory 2. Objectives 1.2 Students will provide evidence that temperature is the measure of the motion of molecules 3. Reasons for content and Having the students work on a direction for the content again instructional strategy gives them ownership of the class and gives them more of an investment into the material itself Having the students get up out of their seats and move around will help the tactile learners in the classroom have a part of the lesson that they can connect to more easily The activity of modeling KMT helps the students construct their own rules for how molecules move and how that relates to temperature, which, again, gives them more ownership of the material as they form it and discover it themselves 4. Evidence of understanding Students will justify their rules for molecular motion as it relates to temperature that they devise as a small group Students will apply the what they experienced in the KMT activity to molecules as they generate rules 5. Cultural Responsiveness Students will be drawing on the shared experience they had the previous day as they reexamine what they know and what they still want/need to know. The activity of human modeling of KMT allows those students who learn more tactilely to experience what they are learning in a way they haven’t been able to as easily in the class discussions. 6. Resources Rearrange the room so that students can move around more freely Class list of observations and questions from previous day Guiding questions as students work on building rules around KMT 8 Day 3: Kinetic Molecular Theory—So that’s what heat is! (50 minutes) 1. What students are doing Students begin by reporting out the rules they have constructed the previous day and compile a list of class rules related to KMT Students address the question: What does this molecular motion (really small) look like to us (much bigger)? They reach a point where they may not be able to make the connection between molecular motion and temperature The students receive “just in time instruction” to help guide them to the application of what they learned the previous day about molecular motion They will see examples of KMT in action, both in demo form (food coloring in hot/cold water) and in the form of short applet from the web Students will connect their vocabulary and understanding to that of scientists, specifically “Kinetic Molecular Theory” and temperature as defined as the movement of molecules 2. Objectives 1.1 Students will understand the relationship between molecular movement and temperature 3. Reasons for content and At this point in the instructional flow, the students will have instructional strategy reached a point where most cannot make sense of what they observed the previous day (ie how does the activity relate to real life and something observable) Interactive concept building allows the students to continue to maneuver the material themselves, but also brings the teacher in to help them and add information they would otherwise be unable to understand KMT is a concept that is foundational to the rest of the understanding of heat transfer; it is the way science understands heat 4. Evidence of understanding Student comments and questions will demonstrate where they are and what aspects of KMT they are understanding Students will use what they have learned about KMT to explain why food coloring spreads faster in hot water than in cold water Students will apply the concept of KMT to density later in the unit 5. Cultural Responsiveness By building on the experience and vocabulary the students have been using for the different phenomena they have been observing, students are more able to synthesize the new information and terms they need to learn into what understandings they already have. 6. Resources Food coloring, warm water, cold water, two clear plastic cups http://mc2.cchem.berkeley.edu/Java/molecules/index.html 9 Day 4: Conduction—Mom, he’s touching me! (50 minutes) 1. What students are doing Students are introduced to the idea of an insulator via their ideas being elicited about a thermos (what it does, when you use it, how it does what it does?) (hook) Students then stand in a single file line around the classroom and devise a way to get a ball (“energy ball”) from one end of the line to the other with the stipulation: a student must always be toughing the ball Students debrief the activity in small groups and work on guiding questions to synthesize the passing energy (conduction) activity with a thermos keeping things hot/cold Then students will discuss their findings with the whole class and contribute factors for the model of a thermos Students see a model constructed by the teacher for how a thermos works, and briefly discuss what a scientific model is Students make connections between conduction and how a fire transfers heat energy (knowledge base) 2. Objectives 2.1 Students will understand that heat energy can be passed by things touching each other (conduction) 3. Reasons for content and This is the set up of background information for the inquiry the instructional strategy students will do the next several days. This gives the students an understanding of conduction so they can work on reducing it in their own insulators The thermos gives the students a concrete example of an insulator, as well as how conduction plays out in everyday life Students will be exposed to scientific models here so that they can have experience with them by the time they begin work on their culminating project for the unit (designing a model) 4. Evidence of understanding Students will apply the experience with the energy ball to the guiding questions to begin to explain a thermos/insulator Students will critique the findings of fellow groups to refine the class understanding of conduction 5. Cultural Responsiveness Bringing the thermos into class gives those students who may have never had experience with them the opportunity to see and feel the example for conduction. This is also a chance for those students who do know about thermoses to help teach the other students, giving them a chance to express their knowledge and understanding in a positive, validating environment. The energy ball activity gives students a concrete way of thinking about conduction which should be simple enough to cross cultural and SES boundaries. It reaches out to the tactile learners, while the group discussions meet the needs of the auditory learners. The visual learners can watch the passing of the energy ball, can see a thermos first hand, and get to examine 10 the model for a thermos 6. Resources A thermos Energy ball Guiding questions on worksheet Model of thermos 11 Day 5: Conduction Inquiry—I like my temperature (50 minutes x 2 days) 1. What students are doing Students are given a hand out to read about heat insulators with some background information on how they operate (knowledge base) Students are given a class model from teacher to start out with for their insulator (initial model) Students are broken into their lab groups and given a task to complete: design an insulator that can moderate the temperature (energy transfer) within a specific margin Groups develop a rationale for the way they are designing their insulator (predictions) Students set up a procedure for building their insulator and begin construction (design investigation) 2. Objectives 2.2 Students will apply their understanding of conduction needing contact between substances to transfer heat energy 3.4 Students will construct an experimental procedure based on a model given to them 3. Reasons for content and There are multiple ways students could decide to design their instructional strategy insulator, giving them much freedom of choice and involvement. It also allows them to see what other students in the class have devised and what different options are available to them The rationale for their design allows them to demonstrate their understanding of convection, as well as coming to a group consensus on how and why they are designing their insulators a specific way 4. Evidence of understanding Group rationales will show the underlying scientific concepts the students are using to design their insulators 5. Cultural Responsiveness Students will have group roles to help each student feel included in the inquiry and be able to contribute to the group product in a positive way. The students are also given freedom in how they set up their insulator and are allowed to be creative, which allows for different cultural understanding to shine through as needed. The composition of the lab groups will reflect diversity in gender, race/ethnicity, and SES, as well as the level scientific understanding. 6. Resources Initial model to present to the students A thermos (used previous day) to remind students of what they talked about in regards to insulators the previous day Equipment available to students to construct insulators (currently unsure of what materials will be used) 12 Day 6: Insulator Contest and Data Analysis—Why does theirs work too? (50 min.) 1. What students are doing Students run a test on their insulators they designed the previous day. One test is done w/ hot water inside and cold water outside. The other test is done w/ cold water inside and hot water outside (conduct investigation) Students take data on how much the temperature of the water changes when they use their insulator Students walk around the room and look at the different designs the other groups have devised Students compare data with other groups/insulator designs and see if any insulator performed better than another (analyze data) The class discusses the data they have found and possibilities for why a given insulator may have been more effective than another Students examine several revised models and decide as a class which one best represents their data and why (revise model) 2. Objectives 3.3 Students will support a revised model of insulators 3.5 Students will analyze experimental designs and determine the factors that are important for insulators 3. Reasons for content and This inquiry gives the students a chance to have a little healthy instructional strategy competition (healthy because the challenge can motivate, but grades are not based on who “wins”). By having the students look at what other groups have come up with as their insulators it reinforces the idea that there are often multiple ways to approach a scientific problem that are equally valid Comparing student data gives them a chance for error analysis (if there’s another group w/ a similar design), as well as the beginning of understanding how different insulators may function better or worse than others Students are not asked to design their own models at this point because it is still early in the year. It is also another form of modeling how to model for the students so that they can be prepared for their own model construction by the end of the unit 4. Evidence of understanding Students will justify their selection of the best final model Students will verify their data with other groups that have similar insulator designs Students will generalize their findings in their competition to explain how insulators (and conduction) work 5. Cultural Responsiveness A variety of insulator ideas are represented in this inquiry. The difficulty is to not devalue the work of any group that is not as successful at insulating as another group. Instead, this could be turned into a chance to draw out learning about insulators and conduction; concepts that can be applied regardless of how well the insulator itself performed. 13 6. Resources Each of the lab groups’ insulators designed from the previous class day Thermometers Directions/procedure on how to run the insulator test Set of final models for students to choose from (some clearly better than others) 14 Day 7: How light at heat are related—I see that heat! (50 minutes) 1. What students are doing Students begin by investigating nigh vision goggles. They brainstorm how its possible to see in the dark Students review what they learned the previous year about light and what it takes for us to see things They break into small groups and take what they know of light and try to come up with an explanation of how we could see in the dark. They work through guiding questions on a worksheet They then come back to whole group and quickly present the ideas they came up with to the rest of the class Next the students are split in half, each of which is sent to one portion of the room. The students are then given the task of determining how to get a ball (represents energy) from one group to the other without moving from their position Students then receive “just in time” instruction that pushes them to understand how heat can be a form of light and thereby energy, as well as how radiant energy does not require a medium to transfer heat Now students brainstorm places they have encountered heat that does not need to make contact to be transferred (radiation) (sun, fire, etc) 2. Objectives 2.3 Students will explain how radiant heat is transferred (does not need a medium) 3. Reasons for content and The idea of being able to see in the dark is one that can instructional strategy potentially be interesting and, more importantly, complex and perplexing to students. Opening the class w/ the idea of night vision goggles gives them a problem to work on, as well as a way to begin to solve that problem. It forces them to begin to apply and integrate what they’ve learned so far about energy, as well as what they remember about light By reviewing the mechanics of light as a whole class, those students who remember from the previous year help to teach/explain those concepts to the rest of the class rather than it coming from the teacher. Armed w/ the understanding of light, students have the tools necessary to problem solve night vision goggles The energy transfer activity reminds the students of the previous activity involving conduction and furthers the idea that heat energy can be transferred in different ways. It also gives the tactile learners a “hands on” active type of instruction Radiation follows conduction because the most intuitive way of understanding heat transfer is touch, and it is difficult to talk about transfer w/o a medium before talking about transfer using a medium Again, letting students construct their own rules/ideas behind 15 how night vision works allows them to have ownership if the ideas and concepts 4. Evidence of understanding Students’ presentations of how they think night goggles work has them construct an argument based on the scientific ideas they know/understand Students interpret the energy ball activity in terms of energy transfer (and ultimately radiative energy) 5. Cultural Responsiveness This lesson allows students to work through the ideas both intellectually and physically. The group presentations allow the verbal learners to interact in a way close to their learning style. The tactile learners’ needs are met through the energy ball activity. Visual learners will see pictures of night vision goggles as well as the images they produce and have the option of drawing their group’s explanation. Night vision goggles may be something unfamiliar to all students, but by using images it can be made more accessible to all students. Most students probably do not know how they work, so in that way they are all on a similar playing field. 6. Resources http://science.howstuffworks.com/nightvision3.htm Worksheet of guiding questions for night vision problem Energy ball List of rules/constraints for the transfer activity on board 16 Day 8: Convection—Heat moves me (50 minutes) 1. What students are doing Students will observe a demonstration of convection and describe/draw a diagram explaining how they see the heat being transferred in the system Students will discuss in pairs what they observed and what forms of energy transfer they think they saw. They will also compile a list of questions/things that they can’t explain They will then share some of their questions with the entire class Next students will receive “just in time” instruction via KMT Students will be given a worksheet of guiding questions to get them to connect the ideas of KMT to density and then buoyancy Students will see how the movement of a fluid that is heated unevenly creates a convection cell They will also see how convection works in our fire example to heat up a room/space Students will receive directions to their convection cell project (culminating assessment) and begin the idea generation process 2. Objectives 2.4 Students will connect density and buoyancy to the creation of a convection cell 4.2 Students will understand that multiple scientific concepts can contribute to the same result 3. Reasons for content and Convection is a complex idea and involves both conduction and instructional strategy radiation. This is why it is the last of the three types of thermal energy transfer to be presented to the students The model gives the students a first-hand visual representation of convection. Because convection often happens on a large scale, it cannot be easily observed. This demo allows the students to have a more concrete way of examining this final form of thermal energy transfer Convection is a complex idea, but it is also a great way to apply the knowledge and understanding the students have accumulated up to this point. The guiding questions help the students to examine what they already know and use that to understand what they don’t yet understand about convection Tying this back to the fire example used at the beginning of the unit helps the students connect it to the other two types of thermal energy transfer The culminating assessment gives the students a chance to demonstrate their mastery of convection through model building, an authentic scientific task. It also involves the complexities of the process it self, lending itself to demonstrating many different scientific concepts at once 4. Evidence of understanding Students will construct connections between density, buoyancy, and convection on their guiding question worksheets 17 Students will explain how the demo works based on their prior knowledge and understanding 5. Cultural Responsiveness Having the students work in pairs can be less intimidating for those students who are less comfortable with both large group discussion and even small group work. Even here at the “end” of the convection road, the students are given the tools to construct their own understanding of convection, with the help of their prior learning, fellow students, and teacher. The demonstration at the beginning of class gives the students yet another shared experience from which they can draw and put their learning into the context of. It helps both the visual and the tactile learners. The verbal learners benefit from the class discussion and the partner time. 6. Resources http://www.eas.purdue.edu/~braile/edumod/convect/convect.htm 1 Glass bread loaf dish, 2 Ceramic coffee cups, 1 small can Sterno or 2 small candles, vegetable oil (about 800-1000 ml), 10 ml (~ 2 teaspoons) thyme, spoon, matches, metric ruler, stopwatch, funnel (to pour oil back into container) Whiteboard/overhead, pens Directions for Convection Modeling Project 18 Day 8: Presentation of Convection Models—Show me what you know (50 minutes) Note: this lesson will fall several days after the previous one to allow students ample time to complete their projects. It may also take 2 days to complete, depending on class size. 1. What students are doing Presenting their Convection Model Projects to the rest of the class in 1-2 minutes Taking simple notes on what their fellow classmates have done for their models and their applications 2. Objectives 3.1 Students will model their understanding of convection in a new system 3.2 Students will understand that scientific phenomena can be modeled in many different ways (writing, pictures/drawing, physical models, etc.) 3. Reasons for content and The students present so that they have a chance to share the work instructional strategy and learning they have done with their peers. It gives them experience doing a “scientific presentation” which is a task authentic to scientist. It also allows them to see many different ways scientific models can be constructed and how many different systems convection exists in our world Taking notes helps keep the students focused on what the presenter is saying, as well as giving them a place to reference both a variety of model types and a range of applications of convection 4. Evidence of understanding Students will explain their model, why they chose it, and the application of it to the real-world system Students will prove they were paying attention by writing notes on the presentations 5. Cultural Responsiveness The presentation lends itself to the auditory and sometimes visual learners. This deficiency is compensated for by the chance for each student to present (tactile learners benefit from presenting) and the variety of ways the students could design their own models. Each student’s model will be respected for it’s uniqueness and creativity and no put-downs of any student’s work will be tolerated. 6. Resources List on board what students should take notes on Grading sheets