CSI: Chemistry. Lesson Created by Brandon Watters, Lakes Community High School

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1 1 CSI: Chemistry Lesson Created by Brandon Watters, Lakes Community High School Purpose The goal of this activity is to reinforce themes taught during a heat and temperature unit. During an inquiry- based activity, students will apply their knowledge to an unknown crime scenario in order to draw a plausible conclusion. Overview During this activity students will investigate a crime scene through both observations and data collection. Using this information, students will write a hypothesis, collect data, and draw a conclusion in order to solve the crime with a plausible explanation. Students will collect temperatures from three different bodies to determine time of death. Time of death will be extrapolated from a student- made graph. Once completed, students will see their journey from start to finish and how they have applied their knowledge of chemistry to solve an unknown scenario. Student Outcomes Illinois State Goal 11: Understand the processes of scientific inquiry and technological design to investigate questions, conduct experiments and solve problems. 11.A.4a: Formulate hypotheses referencing prior research and knowledge. 11.A.4b: Conduct controlled experiments or simulations to test hypotheses. 11.A.4c: Collect, organize and analyze data accurately and precisely. 11.A.4e: Formulate alternative hypotheses to explain unexpected results. 11.B.4f: Evaluate the test results based on established criteria, note sources of error and recommend improvements. Chemistry themes covered: Scientific Process Thermal Equilibrium Heat and Temperature Other: College readiness skills CSI: Chemistry Teacher Overview 3 pages

2 2 Time 1-2 class periods Level 9-12 th grade chemistry class Materials and Tools HP Tablet HP 39gs graphing calculator emulator software Fourier temperature probe (DT029) HP StreamSmart 400 Heat packs Supplies to make bodies (will vary; see Teaching Notes) Preparation Make sure the instructor is comfortable with both the HP tablets and the probeware prior to the activity. Instructors will need to set the crime scene with three bodies, each at a different temperature. Prerequisites This is meant to be a culminating activity for a unit on heat and temperature. The activity will reinforce concepts learned, help students to apply their knowledge to a new scenario, and practice college readiness skills. Background Students will need to utilize the HP tablets and probeware to collect various temperatures in the classroom. Students will need basic graphing and graphical analysis skills. Students should have some knowledge of heat and temperature before activity is performed. Teaching Notes In order for the class to run smoothly the instructor must be comfortable with the HP tablets and probeware. Another key piece to this activity is how the instructor sells the story. If time is taken to create a realistic crime scene and the instructor is in on the story student engagement will increase. An extension for the activity involving specific heat will allow for differentiation for higher thinking groups. The following ideas may help prepare for the activity: Bodies are typically made from clothes stuffed with newspaper. The heat packs can be activated at different times to achieve different temperatures. Place heat packs in the approximate location of the liver, as this is a realistic place to take the temperature of a body. CSI: Chemistry Teacher Overview 3 pages

3 3 It is a good idea to have students take pictures of the bodies with the HP tablets or their cell phones to incorporate into their hypothesis and Lab write- ups. They can also record digital notes using the microphone as well. You may also conduct a mock trial as a follow up to the activity. This would allow the instructor to question each group on their results and do a quick formative assessment of each member. The benefit of this is that the students have fun doing it and the instructor can see what they really know. The class can play the role of jury and call into question poor results and procedures. Additional Information The activity is ideally run with the HP tablets and Fourier probeware (see Adjustments can be made accordingly as the core of the lab is temperature measurements and interpretation of results. The use of technology in the activity helps students to take ownership of their learning and to feel that what they are doing is significant. This work is supported by a grant from Hewlett- Packard under the HP Catalyst Initiative. However, any opinions, findings, conclusions and/or recommendations are those of the investigators and do not necessarily reflect the views of the funders. CSI: Chemistry Teacher Overview 3 pages

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5 1 Name: Date: Welcome to CSI: Chemistry. In order obtain a plausible cause of death and accuse somebody of the crime you will have to work together to gather proof and back up the story you are creating. Please take time to assign specific tasks to each member of your group. Every job is important and failure to do a job correctly may result in the investigation being closed, the crime being unsolved, or even worse a criminal being set free. By signing for a job below you will be taking responsibility for everything related to it. Job descriptions are as follows: Lab Tech. This person will run the hands on portion of the investigation. It is very important to obtain reliable and accurate results, including retesting faulty readings. In some cases there is more than one Lab Tech. You must document everything you do. A jury must be able to retrace your every step. Signature of person(s) in charge: Lead Analyst. This person is in charge of documenting all results provided by the Lab Techs, analyzing the results for bad data, and looking ahead to see what needs to be done next. Signature of person in charge: Evidence Recorder. This person is in charge of recording all observational data during the investigation. This may include quantitative and qualitative observations about the victims or how other CSI partners are collecting data. They should also be protective of all data the investigative team gathers. Signature of person(s) in charge: Welcome CSI s As you are well aware by the gruesome site in the classroom, a terrible crime was committed last night. The chemistry department has gathered some preliminary information for you to examine before you start your investigation. Please follow the necessary guidelines and if you have an idea different from the guidelines talk to the lead investigator of your classroom. When you are ready to begin, read and discuss with your team the crime dossier on the next page.

6 2 Case #1854 Dossier Background Information: Last night a crime was committed on school grounds. As of this moment, you know as much as much as the chemistry department does about what happened. There are a few pieces of advice I can give you that may help on your investigation. We know that over time when two objects of different temperatures are in contact with each other they reach thermal equilibrium. The average temperature of the human body is 37.5 C and it will lose 1.5 C per hour. You may also use the thermal energy equation E = (m)(c p )(ΔT). Use this information to your advantage when determining time of death of each of the bodies. Be accurate in your data readings and specific with your observations and you will be able to build a solid case about this tragedy. Please remember your findings may ultimately be used to convince a jury of your theory. The more solid your case is the more likely you are to be taken seriously. If you have any questions or specific ideas please ask me. I have been designated Lead Investigator for this jurisdiction. Available Equipment: We have equipment that has been allotted to each investigative team. You do not have to use it and you may bring in extra equipment if you think it is necessary. The provided equipment is as follows: HP Tablet Can digitally record observations and data. It can also take pictures and record audio notes to be submitted as evidence. It may provide other programs and information to be determined by investigative team. Fourier temperature probe and software Can sense fluctuations of thermal energy and read average thermal energy over time. This will allow you to take reliable temperature readings. Recommended course of action: Gather observations from the crime scene, create a hypothesis about what happened, gather data, analyze and interpret the data, review your hypothesis, draw conclusions from all available evidence. From this point forward this is your investigation. Take your job seriously, do us proud, and do not let whoever did this get away with it!

7 3 Observations (Include all relevant information including pictures if taken): Victim observations Investigative team observations Initial Hypothesis (What happened/your theoretical story):

8 4 Data Collection (Create an organized data table for your results and record steps): Data collection steps- Data table (Keep in mind the time you take your readings. Add boxes if needed.)-

9 5 Other information: Interpretation of data (What do your results tell you): If you know what temperature a human body is before it begins to cool, and how how much heat it loses per hour you can create a graph to determine time of death. Keep in mind the time you took your temperature readings and label graph accordingly.

10 6 Data extension: In order to strengthen your case you can calculate the amount of energy lost by each body. This will help prove when each person died. The specific heat for the human body is 3.5 J/g C. Use this as well as information previously gathered to determine how much heat was lost for each body. Include all work as evidence. Review Hypothesis (Do your results prove or disprove your idea): Draw final conclusions (Final idea of what happened/final Story to be submitted):

11 7 Investigation review: Before you submit your results to your Lead Investigator, please review your investigation and fill out the following competence exam. The exam is to add credibility to your case and investigative team and avoid falsification of Chemistry Department case files. If you need to you can make more observations and obtain more data readings to add to previous results. Investigative Team Competence Exam: 1. What are possible sources of error in your observations? 2. What are possible sources of error in your data recordings? 3. How confident are you with your investigation results from 1-10? 4. What would help increase your confidence? Can you do anything about this? 5. How do you know who died last? Explain with scientific evidence.

12 8 6. Explain what happens to a human body over time. Use the term thermal equilibrium in your answer. 7. Do you need a reference reading for your temperatures? What would this reading be? Why is it important? 8. Do your temperature readings tell you anything about the crime? How do you know? 9. During your investigation you may have used the equation E = (m)(c p )(ΔT). What does each variable mean? What are the units on each for this investigation? 10. Is there anything that the lead investigator needs to be aware of before the case is permanently filed or submitted to a jury during trial? When you are ready to turn in your case file to the Lead Investigator Please review your materials one last time and have each member sign below. Case files will be retained by the Chemistry Department and submitted for possible use in future court trials. Place signature/job description below