What Factors Affect Heat Absorption? Part 1: Black and ...info.ritenour.k12.mo.us/RSD/science_exemplars/6_8/pdfs/task747.pdf · Properties of matter Transfer and transformation of

What Factors Affect HeatAbsorption? Part 1: Black andSilver Cans

You have been studying aspects of the atmosphere and someconditions that can affect weather. You have also spent timelearning about how to control and test variables using fair tests.For this investigation task, you will be using a model to testwhether darker or lighter surfaces on the earth heat up andwhich surfaces hold their heat longer. A dark can and a silvercan will be heated and then cooled, as you collect your data.

You will observe carefully, measure temperatures over a periodof time and make detailed drawings to show how thesedifferent surfaces react to heat. Use your data to help you todraw conclusions and then relate your findings to whathappens when the sun’s rays hit different areas of the earth.

1 of 28What Factors Affect Heat Absorption? Part 1: Black and Silver Cans

Copyright 2007, Exemplars, Inc. All rights reserved.

What Factors Affect Heat Absorption? Part 1: Black andSilver Cans

Suggested Grade Span

6–8

Task

You have been studying aspects of the atmosphere and some conditions that can affectweather. You have also spent time learning about how to control and test variables using fairtests. For this investigation task, you will be using a model to test whether darker or lightersurfaces on the earth heat up and which surfaces hold their heat longer. A dark can and a silvercan will be heated and then cooled, as you collect your data.

You will observe carefully, measure temperatures over a period of time and make detaileddrawings to show how these different surfaces react to heat. Use your data to help you to drawconclusions and then relate your findings to what happens when the sun’s rays hit differentareas of the earth.

Big Ideas and Unifying Concepts

Cause and effectModelsSystems

Physical Science Concepts

Properties of matterTransfer and transformation of energy

Earth and Space Science Concepts

Earth structure and systemSolar system

Mathematics Concepts

Data collection, organization and analysisMeasurement



Time Required for the Task

One to two class sessions to conduct tests and share/compare results.

Context

This investigation is part of a unit of study on weather for sixth graders. Prior to conducting thisinvestigation, students have learned about the earth’s atmosphere, about isotherms and havepracticed using thermometers and other weather data-collecting devices. This investigationleads to studying about evaporation, the water cycle, relative humidity and how to usebarometers.

Students have also been introduced to our lab-report form and have discussed how to conducta controlled experiment and fair tests. For this investigation, students were provided with thematerials list but expected to write out the procedures their groups used. The focus of thisassessment was on making and recording observations and measurements, and on drawingconclusions that connected to prior ideas and concepts learned about weather.

What the Task Accomplishes

Students use a dark can and a reflective can to understand the concept of heat absorption onthe earth’s surfaces. They are guided to make links to bigger ideas. (For example: How doesthe atmosphere above different surfaces behave when heated/not heated from below by theearth? How does heat absorption vary at different times of the year in different parts of theworld?)

A model sentence is given on the lab form to help students write a cause-effect prediction,based on prior knowledge. Through careful observations and temperature measurementsstudents collect and record data, then generate a new testable question to explore that extendstheir learning from this activity. (See "What Factors Affect Heat Absorption? Part 2: TestingYour Own Question" on this CD-ROM.)

For this lab, students were expected to write their procedures but were given their materials list.The lab-report form includes indicators (written along the left side of the page) to help studentsunderstand what the performance expectations are for each part of the lab. Using the same labform for students in grades four through eight also helps teachers track students’ growth overtime. The small box with each indicator allows the teacher to check if specific evidence isprovided, guiding students to improve investigative skills with further practice.



How the Student Will Investigate

Students work in small groups to set up the lab and conduct their investigations. Beforebeginning, they discuss, as a class, safety procedures for using the heat lamps. Each individualrecords his/her own data and observations. A materials list and data-collection sheet areprovided along with the lab form. The data-collection sheet instructs students to shut off theheat lamp after five minutes, but students continue to collect data on temperature.

The class discusses the lab and safety procedures together, and students record proceduralsteps that will help them as they work. Students generate different possible questions to test,and the class selects one question to investigate. Guiding students to pay attention to waysthey will be sure to conduct fair tests should be part of the discussion as well. Students mayalso want to suggest other ways or other questions to test. These can be done as extensionactivities after the first lab. (See "What Factors Affect Heat Absorption? Part 2: Testing YourOwn Question" on this CD.) While setting up their experiments, students should get minimalhelp from the teacher.

Students used two soup cans, one silver and one black on the outside. (Cans can be coveredwith material or painted to be dark and silver.) They placed thermometers into the top of theopen cans, holding them in place with foam plugs cut to the size of cans. The heat lamp shouldbe an equal distance from both cans. Our students clamped the lamps to the side of the table orsink to stabilize them.

Temperature is recorded for each can every 30 seconds. Once all data are collected, studentsshould review results, look for trends in the data and then draw and write their observations tocomplete the lab report.

Interdisciplinary Links and Extensions

ScienceIn Part 2 of this grade six through eight investigation, students use their “next testablequestions” as the starting point for new investigations with heat absorption. Questions thatnaturally arise are related to putting water and other substances into the cans and repeating theinvestigation. This is a good opportunity to discuss changing only one variable at a time.

Social StudiesHave students create local or global maps showing “dark areas” of the earth’s surface(pavement, bare earth, thick vegetation, etc.) and “light” or reflective areas (glaciers, ice caps,snow-covered surfaces) to depict places where one could predict heat absorption would begreater or less.

Teaching Tips and Guiding Questions

Teachers may want to try this investigation on their own and prepare foam plugs (circles withsmall slits) for the cans before students investigate. When beginning, give students time to work



with their groups to set up the model and solve any problems along the way. Caution studentsto be careful not to look directly at the heat lamp’s light, as it could damage their eyes. Guidingquestions to ask students after they have had time to become fully involved in theirinvestigations might include:

• What have you learned or observed that helped you make a prediction?• Which can do you think will heat up faster? slower?• Which can do you think will hold heat longer?• What would happen if a substance, such as water or soil, was in the cans?• Can you use arrows and labels to make your drawings more detailed?• Do you think you would get different results if the angle of the heat lamp were different (as

with the sun’s rays hitting and heating the earth)?• How can you be sure your temperature readings are accurate?• How long will you continue to collect data?• What do your results tell you? What did you learn from your results?• What conclusions can you make based on your data?• What warms the atmosphere? What areas of the earth would heat up more quickly? (Dark

areas, such as rocks, soil, vegetation, pavement, etc., heat up quickly and radiate theirstored energy as infrared energy after sundown. This energy warms the atmosphere.)

• Why don’t ice- and snow-covered areas heat up easily? (Reflective surfaces absorb littleheat, reflecting the heat energy away from them. This is why in spring, when there is snowon the ground, it feels cooler than in the fall. When the ground is not snow covered, theearth absorbs heat and warms the air above it.)

• Can you show your results in another way? (Graphing results will reveal visually whichsurface lost heat faster or held heat longer, depending on the steepness of the graph.)

• What new questions do you have? What further tests could be run?• Have you learned anything that surprised you?

Concepts to be Assessed

(Unifying concepts/big ideas and science concepts to be assessed using the ScienceExemplars Rubric under the criterion: Science Concepts and Related Content)

Physical Science – Properties of Matter: Students observe physical properties andcharacteristics of (matter) surfaces as they are affected by temperature and transfer heatenergy.

Physical Science – Transfer and Transformation of Energy: Students observe that the sun isa major source of energy for changes on the earth. Students understand that the sun losesenergy by emitting light, which interacts with matter by transmission (including refraction),absorption or scattering (including reflection). Students understand that light waves can betransformed into heat, which moves in predictable ways, flowing from warmer objects to coolerones until both reach the same temperature. Students observe that dark surfaces absorb heatand that reflective surfaces absorb very little heat. Students use the terms temperature, heat,heat absorption, molecules and thermometer appropriately.



Scientific Method: Students describe cause-effect relationships with some justification, usingobservations and prior knowledge. Students observe and explain reactions when variables arecontrolled (cause and effect). Students see that how a model works after changes are made toit may suggest how the real thing would work if the same thing were done to it and thatchoosing a useful model (not too simple/not too complex) to explore concepts encouragesinsightful and creative thinking in science, mathematics and engineering (models).

Earth and Space Science – Earth Structure and System; Solar System: Students see thatthe earth and the solar system are a set of closely coupled systems – geosphere (crust, mantle,core), hydrosphere (water), atmosphere (air) and biosphere (all living things) (systems).

Mathematics: Students use precise measurements and collect, organize and analyze dataappropriately.

Skills to be Developed

(Science process skills to be assessed using the Science Exemplars Rubric under the criteria:Scientific Procedures and Reasoning Strategies, and Scientific Communication Using Data)

Scientific Method: Using prior knowledge, predicting/hypothesizing, manipulating tools,observing, collecting, recording and analyzing data, drawing conclusions, making connections,communicating findings, challenging misconceptions and raising new questions.

Other Science Standards and Concepts Addressed

Scientific Method: Students describe, predict, investigate and explain phenomena. Studentscontrol variables.

Scientific Theory: Students look for evidence that explains why things happen and modifyexplanations when new observations are made.

Physical Science – Properties of Matter: Students observe and describe physical propertiesand characteristics of different surfaces and materials, which can then be used to makepredictions and classify materials.

Physical Science – Transfer and Transformation of Energy: Students observe that the sun isa major source of energy for changes on the earth. Students understand that the sun losesenergy by emitting light and that light arrives in a range of wavelengths, consisting of visiblelight as well as infrared and ultraviolet radiation. Students recognize that light waves can betransformed into heat and that light interacts with matter by transmission (including refraction),absorption or scattering (including reflection). Students understand that energy is a property ofmany substances and is associated with heat, light, electricity, mechanical motion, sound,nuclei and the nature of a chemical.

Earth and Space Science – Earth Structure and System: Students observe how water, whichcovers the majority of the earth’s surface, circulates through the crust, oceans and atmosphere



in what is known as the water cycle. Students understand that the atmosphere has differentproperties at different elevations and is heated by the earth’s surface below.

Earth and Space Science – Solar System: Students observe that the sun is the major sourceof energy for phenomena on the earth’s surface (such as the growth of plants, the winds, theocean currents and the water cycle).

Suggested Materials

Groups of two to four students will each need timer with a second hand, a dark can and a lightor silver-colored can, two foam plugs with slits in the centers to seal the top of each can, twothermometers, and a heat lamp and a clamp. Lab-report forms, with data-collection sheets, arecompleted by each individual student. Refer to the worksheets on pages 9–12.

Possible Solutions

Groups of students must create a model using two cans, according to procedures discussed atthe start of the lab. Students should write a cause-effect prediction, based on prior knowledge,and give a plausible reason for their hypothesis. For this lab, students were expected to writetheir procedures but were given a list of materials. Students need to identify the independentvariable (color of can) and dependent variables (distance from lamp, size and material of cans,foam on both, etc.) Observations should include details and a drawing with supporting labels.Drawings should indicate clearly which can is which and show equal distances from the heatlamp. A summary of results (data) should be used to draw conclusions. A new testablequestion, which builds from this investigation, should be suggested.

Task-Specific Assessment Notes

NoviceThis student completes the task, but the solution is lacking in details and conceptualunderstanding. The hypothesis does include a reason as to why the prediction is made;however, the student does not use the “if-then” form to state the hypothesis. The independentvariable is named appropriately but constants are not. The student appears to confuseprocedures with constants. The student’s drawing is not labeled and does not showthermometers in the cans. No observations are made, but the student suggests a possiblesource of error for an observation. The summary is accurate but limited and does not use actualdata. Conclusions try to link data to the hypothesis, but the student is unable to makeconnections to science concepts learned. There is an attempt to raise a new question for furtherexploration.

ApprenticeThis student’s solution is lacking in detail, although the task is completed. The hypothesisattempts to use science terms (photons) but does not use them correctly and is not in “if-then”format. The student correctly names the independent variable and identifies some constants.Procedures are not clear enough to be replicated but give a general idea of what is actuallydone. Drawings are included but are not clearly labeled and lack important parts. The



observations are accurate and relevant but do not differentiate between the two cans.Conclusions do not link data to hypothesis, but a trend is correctly identified. Conceptualunderstanding is weak; there is no attempt to link learnings to bigger ideas of weather. A newquestion is raised for further testing.

PractitionerThis student states a testable question and follows through to complete the task. The solution iscomplete and all necessary parts of the lab report are present. Procedures are detailed andshow concern for accuracy and fair testing. Drawings include clear labels and enough details sothat they enhance understanding. Observations are accurate and relevant. General trends arenoted in the summary, but differences in rates of heating for the black and silver cans are notdiscussed. Conclusions clearly link to the hypothesis; links to science concepts are implied butnot stated explicitly. Two “new” questions build upon the last question tested.

ExpertThis student’s solution is complete and detailed. The hypothesis and reasoning are well-writtenand include all independent and dependent variables. Procedures are clear and can easily bereplicated. There is a well-labeled drawing, and observations are detailed to enhanceunderstanding. Observations of both heating and cooling show some extended thinking. Thestudent’s summary is detailed, refers to data collected and links light energy to heat energy.Conclusions are supported by data and link to the hypothesis. There is evidence of conceptualunderstanding and extended thinking in the discussion of sources of error, connections aremade to prior investigations and there is a further question to test.











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What Factors Affect Heat Absorption? Part 1: Black and ...info.ritenour.k12.mo.us/RSD/science_exemplars/6_8/pdfs/task747.pdf · Properties of matter Transfer and transformation of