Problem statement, Standards, Data and Technology

Transcription

1 PURDUE UNIVERSITY INSTRUMENT VAN PROJECT Lesson Plan Title: Nuclear Energy Teacher Name: Tim Haberfield NUCLEAR SPECTROMETRY School: Kokomo High School Subject: Chemistry I Grade Level: Problem statement, Standards, Data and Technology Asking questions and defining problems Establish driving question for the lesson plan or define problem students will be solving. Attach any documents used to establish the driving question or define the problem. How can an adequate nuclear waste container be designed? Incorporating Next Generation Science Standards, Common Core, or State Standards State the standards that will be covered during this lesson plan. Include all standards which may apply (NGSS, Common Core, or State Standards). Obtaining and evaluating information C.2.6 Describe nuclear changes in matter, including fission, fusion, transmutations, and decays. C.2.7 Perform half-life calculations when given the appropriate information about the isotope. Students will perform 3 labs, and take notes from the video The Eyes of Nye Nuclear Energy. In the three labs the students will be using Nuclear Scalars to collect data about radioactive, shielding of

2 PURDUE UNIVERSITY INSTRUMENT VAN PROJECT NUCLEAR SPECTROMETRY How will students be obtaining and/or collecting the information? radioactive, and the half-life of an isotope. The data will be used in the design of a nuclear waste container. The video will provide information to the students about the use of nuclear energy. The video will review the type of nuclear changes (fission, fusion, transmutation, and nuclear decay) and will give insight on the advantages and difficulties in implementing nuclear energy. (see appendix 1 for the lab procedures and questions for the three labs, the nuclear container design sheet, and the requirement for a persuasive letter to a legislator about nuclear energy)

3 PURDUE UNIVERSITY INSTRUMENT VAN PROJECT NUCLEAR SPECTROMETRY Analyzing and interpreting data How will students be analyzing and interpreting the collected data? In the nuclear container design teams the students will take the data from the three labs and will calculate the thickness and durability their container will need to have in their design. The persuasive letter to a legislator the students will use the information they learned through the class and presented in the video The Eyes of Nye Nuclear Energy to support or refute nuclear energy. Use of technology and software Indicate the type of technology and software students will be using in order to implement this lesson plan. Students will have the opportunity to use nuclear scalers, and the students will write their letters on Google Docs. Collaboration, critical thinking and communication Collaboration Indicate how students will be collaborating during the implementation of the lesson plan Students will be working in two different teams. The first is a lab group in which the students will collect data with nuclear scalers. Then the lab groups will share their data with the entire class. The students will be grouped into design teams to calculate the amount of shielding and the durability they will need for the nuclear waste container. The design team must agree on a final design to be submitted. The students will choose the groups for the labs, but the students will be assigned to the design teams. Critical Thinking How will the students evaluate the question or defined problem to reach an objective conclusion? How will the students being using the learned content and collected The Students will use the data gathered from the nuclear scalars to the think critically about the design of their nuclear container. The information the students have learned about nuclear chemistry with the information presented in the video The Eyes of Nye Nuclear Energy the students will need to think critically about the concerns of storing nuclear waste and the continued use of nuclear reactors. References Cited

4 PURDUE UNIVERSITY INSTRUMENT VAN PROJECT NUCLEAR SPECTROMETRY data to be able to critically think about the established question and/or problem on this lesson plan? * Science Express Nuclear Scalar Labs * The Eyes of Nye Nuclear Energy video Communication How will the students communicate their findings and conclusion regarding the established question and/or problem? References Teacher s References Include all references used to develop and implement this lesson plan. The students will communicate their findings through the completion of the three labs and their questions. The nuclear container design and the student s letters to a legislator. Purdue Science Express Nuclear Scaler Labs (see Appendix 1) and The Eyes of Nye Nuclear Energy video are the two references the teacher will need. If a teacher is unable to be in the Purdue Science Express program Appendix 2 will give ideas how to complete this lesson. Student s References Include all references students will need to complete this lesson plan. The printouts of the Purdue Science Express labs, the nuclear waste container design sheet, and the letter to a legislator writing prompt and the letters requirements. Assessment Plan

5 PURDUE UNIVERSITY INSTRUMENT VAN PROJECT NUCLEAR SPECTROMETRY Assessment Plan How will the students be assessed during and/or at the end of the lesson plan? The students will be assessed through the completion of the lab sheets and questions, the design team final nuclear waste container, and the letter to a legislator. See appendix 1 for the resources. Include resources that will be used to assess the students for the lesson plan.

6 PURDUE UNIVERSITY INSTRUMENT VAN PROJECT NUCLEAR SPECTROMETRY Resources and Costs Resources Needed List all the resources needed (equipment, facilities, materials or any other resources). Purdue Science Express for the nuclear scalers The video The Eyes of Nye Nuclear Energy Costs List the estimated cost of implementing this lesson plan. Include all costs related to equipment, materials and any resource critical to the implementation of the lesson plan. The cost of enrollment in the Purdue Science Express program. The Video The Eyes of Nye Nuclear Energy should be available free through any computer video wed sites. Implementation Plan Implementation Plan Timeline Establish the timeline to implement the lesson plan. Provide an estimate of time and days in order to complete the lesson plan. The lesson should start after the completion of nuclear chemistry. The lesson should take six (50 minute) class periods. Three (50 minute) class periods will be needed to complete the three labs. One (50 minute) class period for design team activity. One (50 minute class for watching and note taking from the video The Eyes of Nye Nuclear Energy. One (50 minute) class writing the legislator letter.

7 PURDUE UNIVERSITY INSTRUMENT VAN PROJECT NUCLEAR SPECTROMETRY

8 PURDUE UNIVERSITY INSTRUMENT VAN PROJECT NUCLEAR SPECTROMETRY Appendix 1 RADIOACTIVITY (Revised: ) INTRODUCTION The nuclei of certain atoms are stable and under ordinary circumstances, stable nuclei do not undergo change. The nuclei of other atoms are unstable. These nuclei undergo change spontaneously, that is, without outside help. When unstable nuclei undergo change they give off radiation. Atoms which have unstable nuclei are radioactive and are called radioisotopes or radionuclides. The change that an unstable nucleus undergoes is called disintegration or decay. When unstable nuclei disintegrate, or decay, certain particles - alpha or beta particles - or bundles of energy called gamma radiation, are emitted. Atoms and molecules in the path of radiation are ionized, that is, they are stripped of electrons. That means alpha particles, beta particles, gamma radiation and other nuclear emissions have enough energy to remove some electrons from atoms or molecules with which they collide. Positively charged particles and free electrons are left behind after the collisions. Devices that are used to detect radioactivity are based on the ionizing ability of radiation. One such device is the Geiger-Muller tube which is connected to a counter and is commonly referred to as a nuclear scaler. When a charged particle or gamma radiation enters the Geiger-Muller tube, it ionizes many of the argon gas atoms in the tube. The electrons are attracted to the anode and the argon ions are attracted to the cathode. This produces a surge of current which can be counted by the scaler. PURPOSE To investigate the nature of radioactivity and the effect of time, distance, and shielding materials on various radioactive sources using a G.M. tube with counter (generally referred to as a scaler.) MATERIALS Geiger-Muller tube (nuclear scaler) Radioactive sources for alpha particles, beta particles, and gamma radiation

9 PURDUE UNIVERSITY INSTRUMENT VAN PROJECT Forceps Various shielding materials as provided by the instructor NUCLEAR SPECTROMETRY

10 SAFETY STEM Energy Lesson Plan Elements Inclusion 3 Use forceps or tweezers when handling all radioactive material. Follow the standard safety procedures as explained by your teacher. PRE-LAB QUESTIONS none PROCEDURE NOTE: WHEN NOT IN USE, ALL RADIOACTIVE SOURCES AND OTHER RADIOACTIVE MATERIAL, SUCH AS LUMINOUS WATCH DIALS, SHOULD BE PLACED AT LEAST 1 METER AWAY FOR THE SCALER WHILE MEASUREMENTS ARE BEING TAKEN. PART A: BACKGROUND RADIATION 1. Set the voltage dial on the nuclear scaler at 450 volts or at a voltage given to you by your teacher. 2. Turn the scaler on by pressing <<POWER>> button. The instrument does not need to warmup. 3. Place the empty shield tray in the first shelf slot from the top of the tube. 4. Set the counter interval for 0.5 minutes. 5. Press the <<STOP>> button, then press the <<RESET>> button. At this point, the POWER, STOP and RESET lights should be on, and only zeros will be displayed on the counter. 6. Press the <<COUNT>> button. The scaler will count for the set time interval and stop automatically at the end of the time. At that point the STOP light will come on. Record the final count in your data table. 7. Press the <<RESET>> button. 8. Take 2 more counts for the background reading by pressing the <<COUNT>> button. Press the <<RESET>> button after each count has been recorded. 9. Average the three counts for the background radiation and record your average. Question A-1. What is being counted? Question A-2. Where did it come from? PART B. OBSERVING RANDOMNESS OF DISINTEGRATION 1. Set the counter interval for 0.5 minutes.

11 4 2. Using forceps, place the alpha source on the plastic holder and place it on the first shelf position from the top. 3. Press the <<COUNT>> button and record the count when the STOP light comes on. 4. Press the <<RESET>> button. 5. Repeat the count of the alpha source on the first shelf two more times. Record your results. Question B-1. Compare the three values. Are they exactly the same, very close, or very different? Question B-2. What do these results indicate about the nature of radioactive decay? PART C. THE EFFECT OF TIME ON THE AMOUNT OF EXPOSURE TO RADIATION 1. Set the counter interval for 0.5 minutes. 2. Using forceps, place the beta source in the plastic holder and place it in the third shelf position from the top. 3. Press the <<COUNT>> button. After the STOP light comes on, record the number of counts on the display. 4. Press the <<RESET>> button. 5. Set the counter interval for 1.0 minutes. 6. Press the <<COUNT>> button. After the STOP light comes on, record the number of counts on the display. 7. Press the <<RESET>> button. 8. Set the counter interval for 2.0 minutes. 9. Press the <<COUNT>> button. After the STOP light comes on, record the number of counts on the display. 10. Press the <<RESET>> button. Question C-1. From your data, what conclusions can you make concerning time and the amount of exposure to radiation you received? Question C-2. Predict the approximate number of counts you would measure in 3 minutes. Question C-3. Approximately how many counts would you observe in 24 hours?

12 PART D. THE EFFECT OF DISTANCE ON THE AMOUNT OF EXPOSURE TO RADIATION 5 1. Set the counter interval to 0.5 minutes. 2. Place an empty plastic shield tray in the first shelf position from the top. 3. Using forceps, place the beta source in the plastic holder and place it in the second shelf position from the top. 4. Press the <<COUNT>> button. After the STOP light comes on, record the number of counts on the display. 5. Press the <<RESET>> button. 6. Move the plastic tray containing the beta source to the third shelf position from the top. The empty plastic tray should remain in the first shelf position. 7. Press the <<COUNT>> button. After the STOP light comes on, record the number of counts on the display. 8. Press the <<RESET>> button. 9. Move the plastic tray containing the beta source to the fourth position, then the fifth position and finally the sixth position, counting the radiation at each level. Question D-1. From your data, why is it preferable to build a nuclear power plant in a sparsely populated area rather than close to a big city? PART E. THE EFFECT OF SHIELDING ON THE AMOUNT OF EXPOSURE TO RADIATION. SECTION 1. BETA PARTICLE RADIATION 1. Set the counter interval to 0.5 minutes. 2. Place an empty plastic shield tray in the first shelf position from the top. 3. Using forceps, place the beta source in the plastic holder and place it in the second shelf position from the top. 4. Press the <<COUNT>> button. After the STOP light comes on, record the number of counts on the display. 5. Press the <<RESET>> button. 6. Place a piece of notebook paper on the plastic shield tray in the first shelf position.

13 7. Press the <<COUNT>> button. After the STOP light comes on, record the number of counts on the display Press the <<RESET>> button. 9. Replace the notebook paper with another shielding material. 10. Press the <<COUNT>> button. After the STOP light comes on, record the number of counts on the display. 11. Press the <<RESET>> button. 12. Use other shielding materials and take the count as directed by your teacher. SECTION 2. ALPHA PARTICLE RADIATION Follow the procedure outlined in Part E, Section 1 but use an alpha source instead of a beta source. SECTION 3. GAMMA RADIATION Follow the procedure outlined in Part E, Section 1 but use a gamma source instead of the beta source. Question E-1.Which source (beta, alpha, or gamma) is most easily shielded? Question E-2.Which source is the least easily shielded? Question E-3.Which of the shielding materials was the most effective? Question E-4.Which of the shielding materials was the least effective? DATA ANALYSIS AND CALCULATIONS 1. Using your textbook as a resource, describe an alpha particle, a beta particle and gamma radiation. 2. Is there a correlation between the mass of the particle radiated and the ease with which it is shielded? 3. Predict the effect on the count for each source if the source had been shielded by two pieces of notebook paper rather than just one. 4. Predict the effect on the count for each source if the source had been shielded by five pieces of notebook paper rather than just one. 5. Graph of distance vs. count.

14 i. Using your data for PART D, subtract the average background count from the count at each level. This adjusted count is that which is produced by the source. ii. Plot a graph of the distance from the source vs. the adjusted count. The distance should go on the horizontal axis and the adjusted count should go on the vertical axis. 6. Describe the relationship between the amount of radiation and the distance from the source. 7. The activity of a radioactive source is 500 counts at a distance of 10 cm. What would be the approximate activity if the source was moved to a distance of 20 cm? 8. How would your exposure to radiation from the sun differ if you were on the planet Mercury or on the planet Pluto? 7

15 NAME CLASS PERIOD STEM Energy Lesson Plan Elements Inclusion 8 PART A: BACKGROUND RADIATION RADIOACTIVITY DATA SHEET Trail Number Count/ 0.5 min Average Background Question A-1: What is being counted? Question A-2: Where did it come from? PART B: RANDOMNESS OF DISINTEGRATION Trail Number Count/ 0.5 min Question B-1. Compare the three values. Are they exactly the same, very close, or very different? Question B-2. What do these results indicate about the nature of radioactive decay?

16 9 PART C: THE EFFECT OF TIME ON THE AMOUNT OF EXPOSURE TO RADIATION Time Interval Count 0.5 min 1.0 min 2.0 min Question C-1. From your data, what conclusions can you make concerning time and the amount of exposure to radiation you received? Question C-2. Predict the approximate number of counts you would measure in 3 minutes. Question C-3. Approximately how many counts would you observe in 24 hours?

17 PART D. THE EFFECT OF DISTANCE ON THE AMOUNT OF EXPOSURE TO RADIATION 10 Shelf Position Distance From Source Count 2 nd From Top 2 cm 3 rd From Top 3 cm 4 th From Top 4 cm 5 th From Top 5 cm Bottom 6 cm Question D-1. From your data, why is it preferable to build a nuclear power plant in a sparsely populated area rather than close to a big city? PART E. THE EFFECT OF SHIELDING ON THE AMOUNT OF EXPOSURE TO RADIATION Shielding Material Beta Count Alpha Count Gamma Count notebook paper Question E-1. Which source (beta, alpha, or gamma) is most easily shielded? Question E-2. Which source is the least easily shielded? Question E-3. Which of the shielding materials was the most effective? Question E-4. Which of the shielding materials was the least effective?

18 11 DATA ANALYSIS AND CALCULATIONS 1. Using your textbook as a resource, describe an alpha particle, a beta particle and gamma radiation. 2. Is there a correlation between the mass of the particle radiated and the ease with which it is shielded? 3. Predict the effect on the count for each source if the source had been shielded by two pieces of notebook paper rather than just one. 4. Predict the effect on the count for each source if the source had been shielded by five pieces of notebook paper rather than just one. 5. Graph of distance vs. count. i. Using your data for PART D, subtract the average background count from the count at each level. This adjusted count is that which is produced by the source. ii. Plot a graph of the distance from the source vs. the adjusted count. The distance should go on the horizontal axis and the adjusted count should go on the vertical axis. 6. Describe the relationship between the amount of radiation and the distance from the source. 7. The activity of a radioactive source is 500 counts at a distance of 10 cm. What would be the approximate activity if the source was moved to a distance of 20 cm?

19 12 8. How would your exposure to radiation from the sun differ if you were on the planet Mercury or on the planet Pluto? LAB WRITTEN BY: CAROL CHEN, DAN CLARK, RICK HEASTON, AND PRU PHILLIPS

20 TEACHERS' GUIDE RADIOACTIVITY 13 CLASSROOM USAGE This is considered a discovery lab. It may be appropriate for physical science as well as practical and college prep chemistry classes. CURRICULUM INTEGRATION Nuclear Energy - this may be done anytime while studying the unit. PREPARATION Shielding materials have to be provided. Some things which can be used are plastic wrap, aluminum foil, a piece of fabric. lead foil, window glass, wood (tongue depressors), tissue, and cotton. GETTING READY It is important to familiarize yourself with the set-up and operation of the nuclear scaler. Our scalers work at the 450 volt setting, but it would be best to verify that this is a good operating voltage. You will probably want the students to work in pairs. TIME This experiment will probably require two lab periods. SAFETY AND DISPOSAL The radioactive sources will not provide any unusual hazard for the students. They should handle the samples with forceps. If there is a concern about having touched a sample, washing the hands will be sufficient. VARIATIONS This lab may be expanded, cut back, or rearranged to fit your schedule. You may want the students to bring in some different materials. Some students may want to change the time intervals.

21 14 RADIOACTIVITY (Revised ) INTRODUCTION The nuclei of certain atoms are stable and under ordinary circumstances, stable nuclei do not undergo change. The nuclei of other atoms are unstable. These nuclei undergo change spontaneously, that is, without outside help. When unstable nuclei undergo change they give off radiation. Atoms which have unstable nuclei are radioactive and are called radioisotopes or radionuclides. The change that an unstable nucleus undergoes is called disintegration or decay. When unstable nuclei disintegrate, or decay, certain particles - alpha or beta particles - or bundles of energy called gamma radiation, are emitted. Atoms and molecules in the path of radiation are ionized, that is, they are stripped of electrons. That means alpha particles, beta particles, gamma radiation and other nuclear emissions have enough energy to remove some electrons from atoms or molecules with which they collide. Positively charged particles and free electrons are left behind after the collisions. Devices that are used to detect radioactivity are based on the ionizing ability of radiation. One such device is the Geiger-Muller tube which is connected to a counter and is commonly referred to as a nuclear scaler. When a charged particle or gamma radiation enters the Geiger-Muller tube, it ionizes many of the argon gas atoms in the tube. The electrons are attracted to the anode and the argon ions are attracted to the cathode. This produces a surge of current which can be counted by the scaler. PURPOSE To investigate the nature of radioactivity and the effect of time, distance, and shielding materials on various radioactive sources using a G.M. tube with counter (generally referred to as a scaler.) MATERIALS Geiger-Muller tube (nuclear scaler) Radioactive sources for alpha particles, beta particles, and gamma radiation Forceps Various shielding materials as provided by the instructor 250 ml Beaker Ring Stand 3-Prong Clamp For the extra extensions of the lab: Empty paint can ph probes Soil, rock, sand, etc. Plastic jewelry baggies SAFETY Use forceps or tweezers when handling all radioactive material.

22 15 Follow the standard safety procedures as explained by your teacher. PRE-LAB QUESTIONS none PROCEDURE NOTE: WHEN NOT IN USE, ALL RADIOACTIVE SOURCES AND OTHER RADIOACTIVE MATERIAL, SUCH AS LUMINOUS WATCH DIALS, SHOULD BE PLACED AT LEAST 1 METER AWAY FOR THE SCALER WHILE MEASUREMENTS ARE BEING TAKEN. PART A: BACKGROUND RADIATION 1. Set the voltage dial on the nuclear scaler at 450 volts or at a voltage given to you by your teacher. 2. Turn the scaler on by pressing <<POWER>> button. The instrument does not need to warmup. 3. Place the empty shield tray in the first shelf slot from the top of the tube. 4. Set the counter interval for 0.5 minutes. 5. Press the <<STOP>> button, then press the <<RESET>> button. At this point, the POWER, STOP and RESET lights should be on, and only zeros will be displayed on the counter. 6. Press the <<COUNT>> button. The scaler will count for the set time interval and stop automatically at the end of the time. At that point the STOP light will come on. Record the final count in your data table. 7. Press the <<RESET>> button. 8. Take 2 more counts for the background reading by pressing the <<COUNT>> button. Press the <<RESET>> button after each count has been recorded. 9. Average the three counts for the background radiation and record your average. Question A-1. What is being counted? Question A-2. Where did it come from? PART B. OBSERVING RANDOMNESS OF DISINTEGRATION 1. Set the counter interval for 0.5 minutes. 2. Using forceps, place the alpha source on the plastic holder and place it on the first shelf position from the top. 3. Press the <<COUNT>> button and record the count when the STOP light comes on. 4. Press the <<RESET>> button.

23 5. Repeat the count of the alpha source on the first shelf two more times. Record your results. 16 Question B-1. Compare the three values. Are they exactly the same, very close, or very different? Question B-2. What do these results indicate about the nature of radioactive decay? PART C. THE EFFECT OF TIME ON THE AMOUNT OF EXPOSURE TO RADIATION 1. Set the counter interval for 0.5 minutes. 2. Using forceps, place the beta source in the plastic holder and place it in the third shelf position from the top. 3. Press the <<COUNT>> button. After the STOP light comes on, record the number of counts on the display. 4. Press the <<RESET>> button. 5. Set the counter interval for 1.0 minutes. 6. Press the <<COUNT>> button. After the STOP light comes on, record the number of counts on the display. 7. Press the <<RESET>> button. 8. Set the counter interval for 2.0 minutes. 9. Press the <<COUNT>> button. After the STOP light comes on, record the number of counts on the display. 10. Press the <<RESET>> button. Question C-1. From your data, what conclusions can you make concerning time and the amount of exposure to radiation you received? Question C-2. Predict the approximate number of counts you would measure in 3 minutes. Question C-3. Approximately how many counts would you observe in 24 hours? PART D. CAN WE DETECT RADIATION IN CELL PHONES? 1. Set the counter interval to 0.5 minutes. 2. Place a cell phone in the tube. 3. Run three different tests to test for ionizing radiation from your cell phone. First with the phone simply on, then with the phone receiving a text, and lastly with the phone receiving a call. Question D-1. What are current forms of ionizing radiation that we receive in our lives? How do we protect ourselves against them? Question D-2. From your data, what conclusions can you make concerning the amount of ionizing

24 radiation that the cell phone put out? 17 Question D-3. What do, or should, phone manufacturers take into account when designing these cell phones in terms of limiting the amount of ionizing radiation? PART E. THE EFFECT OF DISTANCE ON THE AMOUNT OF EXPOSURE TO RADIATION 1. Set the counter interval to 0.5 minutes. 2. Place an empty plastic shield tray in the first shelf position from the top. 3. Using forceps, place the beta source in the plastic holder and place it in the second shelf position from the top. 4. Press the <<COUNT>> button. After the STOP light comes on, record the number of counts on the display. 5. Press the <<RESET>> button. 6. Move the plastic tray containing the beta source to the third shelf position from the top. The empty plastic tray should remain in the first shelf position. 7. Press the <<COUNT>> button. After the STOP light comes on, record the number of counts on the display. 8. Press the <<RESET>> button. 9. Move the plastic tray containing the beta source to the fourth position, then the fifth position and finally the sixth position, counting the radiation at each level. Question E-1. From your data, why is it preferable to build a nuclear power plant in a sparsely populated area rather than close to a big city? PART F. THE EFFECT OF SHIELDING ON THE AMOUNT OF EXPOSURE TO RADIATION. SECTION 1. BETA PARTICLE RADIATION 1. Set the counter interval to 0.5 minutes. 2. Place an empty plastic shield tray in the first shelf position from the top. 3. Using forceps, place the beta source in the plastic holder and place it in the second shelf position from the top.

25 4. Press the <<COUNT>> button. After the STOP light comes on, record the number of counts on the display Press the <<RESET>> button. 6. Place a piece of notebook paper on the plastic shield tray in the first shelf position. 7. Press the <<COUNT>> button. After the STOP light comes on, record the number of counts on the display. 8. Press the <<RESET>> button. 9. Replace the notebook paper with another shielding material. 10. Press the <<COUNT>> button. After the STOP light comes on, record the number of counts on the display. 11. Press the <<RESET>> button. 12. Use other shielding materials and take the count as directed by your teacher. SECTION 2. ALPHA PARTICLE RADIATION Follow the procedure outlined in Part E, Section 1 but use an alpha source instead of a beta source. SECTION 3. GAMMA RADIATION Follow the procedure outlined in Part E, Section 1 but use a gamma source instead of the beta source. Question F-1.Which source (beta, alpha, or gamma) is most easily shielded? Question F-2.Which source is the least easily shielded? Question F-3.Which of the shielding materials was the most effective? Question F-4.Which of the shielding materials was the least effective? PART G. SHIELDING NUCLEAR WASTE 1. After fuel is spent inside of a nuclear reactor it must be stored temporarily. This is done by placing the spent fuel in pools of water. 2. We will test how deep the pools need to be to safely protect against ionizing radiation from spent fuel. 3. Attach the Geiger-Muller tube to a ring stand with a 3-prong clamp. It must be just tall enough to be able to house the 250 ml beaker. 4. Place the gamma source directly underneath the G-M tube. Take 3 counts with a time interval of 30 seconds.

26 19 5. Next place the 250 ml beaker over the gamma source. Again, take 3 counts. 6. Then add 1 cm. of water to the beaker. Take 3 counts. 7. Continue adding 1 cm. of water and taking 3 counts up to 8 cm. of water. Question G-1. Make a graph of distance of shielding versus counts per half-minute. Question G-2. Draw a best-fit line. The minimum depth that the fuel is placed at is 8 ft. (they are placed much deeper than this though). Using your data, at a depth of 8 ft. how much (in a percent) would the water reduce the original activity of the fuel? EXTENSION ON THIS ASPECT AND IDEAS: 1. This lab is very long. Could be done as a regular chemistry class doing parts A-F. Then part G (with all of its extensions coming after) can be done in another class at a department s discretion (I will be using that part in my environmental science class for instance). 2. Students could also test the water in and of itself after prolonged exposure to radiation samples. This leads to the connection of what happened at Fukushima and how there were worries about the water supply being contaminated. 3. Students could also check to see if ionizing-radiation leads to a ph change in the water. Thus providing a wonderful opportunity to see just how the ecology changes as a result. 4. Could also use things other than water. Ideas thrown out were soil, rock, sand. 5. Also spoke about using a paint can and how well it shields. Students could then design their own nuclear containment container and run with it. Explain their reasoning, have a competition with the entire class, etc. 6. After data is collected talk about local nuclear power plants (Illinois), where the New Madrid fault line is located, its activity in the past. Students could provide a report on possibility for H2O contamination due to nuclear power, earthquakes, accidents, etc. 7. Based on results, would you live next to a power plant, what should we do as a country regarding the expansion of nuclear power, etc. DATA ANALYSIS AND CALCULATIONS 1. Using your textbook as a resource, describe an alpha particle, a beta particle and gamma radiation. 2. Is there a correlation between the mass of the particle radiated and the ease with which it is shielded? 3. Predict the effect on the count for each source if the source had been shielded by two pieces of notebook paper rather than just one. 4. Predict the effect on the count for each source if the source had been shielded by five pieces of notebook paper rather than just one. 5. Graph of distance vs. count.

27 20 i. Using your data for PART D, subtract the average background count from the count at each level. This adjusted count is that which is produced by the source. ii. Plot a graph of the distance from the source vs. the adjusted count. The distance should go on the horizontal axis and the adjusted count should go on the vertical axis. 6. Describe the relationship between the amount of radiation and the distance from the source. 7. The activity of a radioactive source is 500 counts at a distance of 10 cm. What would be the approximate activity if the source was moved to a distance of 20 cm? 8. How would your exposure to radiation from the sun differ if you were on the planet Mercury or on the planet Pluto?

28 21 NAME CLASS PERIOD PART A: BACKGROUND RADIATION RADIOACTIVITY DATA SHEET Trail Number Count/ 0.5 min Average Background Question A-1: What is being counted? Question A-2: Where did it come from? PART B: RANDOMNESS OF DISINTEGRATION Trail Number Count/ 0.5 min Question B-1. Compare the three values. Are they exactly the same, very close, or very different? Question B-2. What do these results indicate about the nature of radioactive decay? PART C: THE EFFECT OF TIME ON THE AMOUNT OF EXPOSURE TO RADIATION

29 22 Time Interval Count 0.5 min 1.0 min 2.0 min Question C-1. From your data, what conclusions can you make concerning time and the amount of exposure to radiation you received? Question C-2. Predict the approximate number of counts you would measure in 3 minutes. Question C-3. Approximately how many counts would you observe in 24 hours? PART D: CAN WE DETECT RADIATION IN CELL PHONES? Phone Scenario Count Turned On Receiving a Text Receiving a Call Question D-1. What are current forms of ionizing radiation that we receive in our lives? How do we protect ourselves against them? Question D-2. From your data, what conclusions can you make concerning the amount of ionizing radiation that the cell phone put out? Question D-3. What do, or should, phone manufacturers take into account when designing these cell phones in terms of limiting the amount of ionizing radiation? PART E. THE EFFECT OF DISTANCE ON THE AMOUNT OF EXPOSURE TO RADIATION

30 23 Shelf Position Distance From Source Count 2 nd From Top 2 cm 3 rd From Top 3 cm 4 th From Top 4 cm 5 th From Top 5 cm Bottom 6 cm Question E-1. From your data, why is it preferable to build a nuclear power plant in a sparsely populated area rather than close to a big city? PART F. THE EFFECT OF SHIELDING ON THE AMOUNT OF EXPOSURE TO RADIATION Shielding Material Beta Count Alpha Count Gamma Count notebook paper

31 24 Question F-1. Which source (beta, alpha, or gamma) is most easily shielded? Question F-2. Which source is the least easily shielded? Question F-3. Which of the shielding materials was the most effective? Question F-4. Which of the shielding materials was the least effective? PART G: THE EFFECT OF DEPTH ON THE AMOUNT OF EXPOSURE TO RADIATION DEPTH Count 0 cm of H2O 1 cm of H2O 2 cm of H2O 3 cm of H2O 4 cm of H2O 5 cm of H2O 6 cm of H2O 7 cm of H2O 8 cm of H2O

32 25 Question G-1. Make a graph of distance of shielding versus counts per half-minute. Question G-2. Draw a best-fit line. The minimum depth that the fuel is placed at is 8 ft. (they are placed much deeper than this though). Using your data, at a depth of 8 ft. how much (in a percent) would the water reduce the original activity of the fuel? DATA ANALYSIS AND CALCULATIONS 1. Using your textbook as a resource, describe an alpha particle, a beta particle and gamma radiation. 2. Is there a correlation between the mass of the particle radiated and the ease with which it is shielded? 3. Predict the effect on the count for each source if the source had been shielded by two pieces of notebook paper rather than just one. 4. Predict the effect on the count for each source if the source had been shielded by five pieces of notebook paper rather than just one. 5. Graph of distance vs. count. i. Using your data for PART D, subtract the average background count from the count at each level. This adjusted count is that which is produced by the source. ii. Plot a graph of the distance from the source vs. the adjusted count. The distance should go on the horizontal axis and the adjusted count should go on the vertical axis. 6. Describe the relationship between the amount of radiation and the distance from the source. 7. The activity of a radioactive source is 500 counts at a distance of 10 cm. What would be the approximate activity if the source was moved to a distance of 20 cm?

33 8. How would your exposure to radiation from the sun differ if you were on the planet Mercury or on the planet Pluto? 26 LAB WRITTEN BY: CAROL CHEN, DAN CLARK, RICK HEASTON, AND PRU PHILLIPS EDITED BY: DEBRA BECK, BECKY CREECH, AND JON GUTHRIE

34 27 TEACHERS' GUIDE RADIOACTIVITY CLASSROOM USAGE This is considered a discovery lab. It may be appropriate for physical science as well as practical and college prep chemistry classes. CURRICULUM INTEGRATION Nuclear Energy - this may be done anytime while studying the unit. PREPARATION Shielding materials have to be provided. Some things which can be used are plastic wrap, aluminum foil, a piece of fabric. lead foil, window glass, wood (tongue depressors), tissue, and cotton. GETTING READY It is important to familiarize yourself with the set-up and operation of the nuclear scaler. Our scalers work at the 450 volt setting, but it would be best to verify that this is a good operating voltage. You will probably want the students to work in pairs. TIME This experiment will probably require two lab periods. SAFETY AND DISPOSAL The radioactive sources will not provide any unusual hazard for the students. They should handle the samples with forceps. If there is a concern about having touched a sample, washing the hands will be sufficient. VARIATIONS This lab may be expanded, cut back, or rearranged to fit your schedule. You may want the students to bring in some different materials. Some students may want to change the time intervals.

35 28 HALF-LIFE OF A RADIOISOTOPE with Nuclear Scalers from Science Express (rev. 6/2015) INTRODUCTION The half-life of a radioisotope is defined as the amount of time necessary for one-half of the quantity of nuclide to decay, i.e., be converted into another species. The conversions involve either alpha or beta particle release, and the reaction can be followed by measuring the number of particles given off. A nuclear scaler will be used to measure the amount of radiation evolved, and graphical interpretations will allow calculation of the half-life. PURPOSE To extend the nuclear chemistry unit to include a simple quantitative study of half-life. SAFETY CONSIDERATIONS Wear disposable gloves when handling the isogenerator column and eluted solutions. At the completion of the experiment, the solutions may be safely flushed down the sink. Gloves and paper towels may be thrown into normal trash containers. PRE-LAB QUESTIONS 1. Write the nuclear equation for the transformation of Cs-137 to Ba-137m. 2. Write the nuclear equation for the transformation of Ba-137m to Ba What trend in the data obtained from the nuclear scaler do you expect? 4. Using counts per minute obtained at time intervals, explain how to graphically determine the half-life. *5. Knowing that the nuclear reaction follows first-order kinetics, how would you more accurately calculate the half-life. (Hint: apply the integrated rate equation.) *AP Level MATERIALS: Per Group Per Class sample planchet 2 isogenerators (Cs-137) water bottle ring stands and clamps waste containers disposable gloves 250 ml beakers deionized or distilled water nuclear scaler sample holder

36 Diluting Solution STEM Energy Lesson Plan Elements Inclusion stopwatch 29 PROCEDURE 1. The nuclear scalers should be set up (450Vv) and background radiation measured. Put radioactive sources from the kits in another part of the room! 2. Wearing disposable gloves, the students should collect 7 drops of the eluate in the planchet and immediately place the sample in slot 2 of the Geiger-Mueller tube. Take a one minute count (time = 1 minute), followed by one minute counts every other minute (t = 1, 3, 5, minutes). 3. The sample planchet may safely be rinsed in the sink with water and dried. Gloves and paper towels may be disposed of in the normal trash cans. 4. The EDTA solution is critical to the success of the experiment. NOTE: Use only Purdue Instrument Van Project supplied solutions!! DO NOT use your own EDTA solution!! Our experience shows this will ruin the column. ANALYSIS/CONCLUSIONS 1. Discuss the shape of the curve obtained from a plot of activity or Counts per minutes versus time. Does it make sense? 2. From your curve in Step 1, determine the half-life of the reaction. Show all work and reasoning.? 3. Why did you wear gloves in the beginning of the experiment, yet were allowed to dispose of materials in the sink and trash can? 4. What is the daughter nuclide formed in this nuclear reaction? Why was EDTA used as the elutant? 5. Why should the concept of half-life of radioisotopes be understood by all citizens, not just chemistry students? 6. *Using your activity/time data and the integrated rate equation for first-order kinetics, calculate the half-life of the reaction. (Hint: least squares program of graphical analysis program, a regression line, or other curve-fitting option).

37 30 TYPICAL CLASSROOM USAGE First-year chemistry AP chemistry CURRICULUM INTEGRATION Radioactivity Half-life of radioactive elements Graphing and interpretation of graphs TEACHERS GUIDE HALF-LIFE OF A RADIOISOTOPE PREPARATION 1. Only materials supplied by the Van Project are to be used. 2. The generator may be milked many times in quick succession without total depletion of the Ba-137 isotope. After three milkings the sample activity will drop to about 1/5 of the initial milking but still produces a satisfactory sample for halflife measurement. 3. Only the qualified instructor should operate the generator. Care should be exercised to avoid spills and contaminating work surfaces. If a spill does occur, the Ba-137 isotope will decay to practically zero activity within 15 min. presenting no waste disposal issue. TIME Prepare Lab: minutes Stopping Point: None Student Time: 30 to 40 minutes SAFETY AND DISPOSAL Solutions may be washed down the drain. Disposable gloves and paper towels may be placed in the normal trash cans. ASSESSMENT Check graphs for correctness Check calculations and results Check answers to Analysis/Conclusions questions Include lab questions in unit test on Nuclear Chemistry CURRICULUM CONNECTIONS Indiana State proficiencies (page 11): 1, 2, 3, 4, 5, 6, 7, 1. Proficiency #3 expanded: Construct a graph and interpret the information.

38 Determine the half-life of Ba-137m. 31

39 32 PRE-LAB QUESTIONS 1. Cs-137 Æ Ba-137m + electron (beta particle) 2. Ba-137m Æ Ba gamma ray 3. Counts per minutes (CPM) will decrease as time increases 4. To graphically determine the half-life: on the graph, choose any point on the curve and note its CPM (counts per minute) on the y-axis and its corresponding time t on the x- axis. Mark this point on the curve. To find the new count which would be detected after one half life of time, divide the marked CPM by 2 (that is, the new count after one half life of time = ). Locate this new CPM point on the curve and note its corresponding value of t. Subtract the two time t values to calculate the amount of time elapsed between the initial reading and the final reading. This amount of time is the half life, which could be symbolized by t ½. 5. The first order rate equation can be written where A o is the initial concentration, A is the concentration at time, t is time, and k is the first order rate constant (slope) (sometimes k is replaced by symbol ) ANALYSIS/CONCLUSIONS 1. The counts/minute decrease as time increases. Yes. 2. Reported value for half life of Ba-137m = t ½ = 2.55 minutes. 3. Sample was radioactive at the beginning of the experiment. The half-life was so short that the radioactivity decreased rapidly and approached background radiation by the end of the experiment. Non-radioactive barium should be disposed of in solid waste; however, the amounts of barium in this experiment are so small that the manufacturer of the isogenerator recommends rinsing the planchets in the sink and drying them for re-use. 4. Ba-137m is a meta-stable isotope of Ba. EDTA is ethylenediaminetetraacetic acid and has the ability to bind (chelate) the metal ion and remove it from the Isogenerator column.

40 33 SAMPLE DATA AND RESULTS: Time (minutes) Adjusted counts per minutes (A) Natural logarithm of adjusted counts per minutes (ln A) A graph of this data Adjusted count vs. time, or A vs. t, yields an hyperbola or inverse (exponential) relationship curve. After graphing ln A vs. t, we observe a regression or best fit line with negative slope: with slope = /minute y-intercept which is ln A intercept = correlation: since the adjusted count will be half of the original count after one half life, then and defining this t will be half life t ½ becomes becomes or so = t ½ = half life

41 34 from the data: t ½ = 0.693/k = 0.693/(0.274/min) = 2.53 min. Writing assignment Writing prompt: At the end of the video Eyes of Nye- Nuclear Energy Bill pleads with the audience to write to their legislator. It the spaces below write the body of a letter to your legislator either supporting or refuting our continued use of nuclear energy. In the letter it does not matter what side of the issue you take, but you opinion must be supported by at least three pieces of evidence supplied in the video or this class. Your body of the letter should be three to five well developed paragraphs. Design sheet. In this activity, you will be analyzing the data from the labs and formulating an idea of how to design a nuclear waste container. Your design needs to shield most of the radiation that would come from plutonium. This shielding can be a composite of materials, layers of metal, concrete, and/or plastic. The second requirement will be the containers durability. The durability is a function of the time it will take to allow plutonium to derogate, so, the container must be able to last several half-lives. Use your data from the half-life lab and the half-lift for plutonium to determine the length of time needed to expose to spent plutonium. Determine how long the shielding materials will last until they erode. Appendix 2:

42 Not all teachers will have excess to nuclear scaler, so here are two low impact ideas that you may be able to use in replacement to the nuclear scalars labs. 35 First to examine half-lives you can find ideas at Second you can have the student research different material s shielding capacity and its durability. SUGGESTED TERMS: Half-life corrected (cpm) graph Ba -137m activity (cpm) nuclear scaler Ba- 137 time solution of EDTA Cs-137 beta (β) particle isogenerator background (cpm) gamma (γ) ray first order rate equation Original lab handout prepared by Mike Grubber and Richard Partezana Lab Revised 7/23/03 by Associate Project Director Instrument Van Project Revised by Debbie Beck., Lafayette Jefferson High School, 6/2015 REFERENCES Procedure for Preparation of Cs-137/Ba-137m Isogenerator Column, (supplied by Oxford Instruments, Inc.) Herron, Dudley J. Et al., Chemistry, D.C. Heath Publishing Company, Lexington, MA. 1993, p. T Cs/Ba-137m Isotope Generator Operating Instructions, (supplied by Spectrum Te

43 36 SUGGESTED TERMS: Half-life corrected (cpm) graph Ba -137m activity (cpm) nuclear scaler Ba- 137 time solution of EDTA Cs-137 beta (β) particle isogenerator background (cpm) gamma (γ) ray first order rate equation Original lab handout prepared by Mike Grubber and Richard Partezana Lab Revised 7/23/03 by Associate Project Director Instrument Van Project, Steven Revised by Debbie Beck., Lafayette Jefferson High School, 6/2015 REFERENCES Procedure for Preparation of Cs-137/Ba-137m Isogenerator Column, (supplied by Oxford Instruments, Inc.) Herron, Dudley J. Et al., Chemistry, D.C. Heath Publishing Company, Lexington, MA. 1993, p. T Cs/Ba-137m Isotope Generator Operating Instructions, (supplied by Spectrum Te