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Nuclear Physics (History, Basics, Theory, Problems and Applications) Summary: The American electorate will need to make educated decisions regarding future energy production. In preparation, students will need to gain an understanding of the foundation and applications of the conservation of energy, energy transfer and technology. The application of nuclear physics is one of many resources that may provide less costly fuels for future energy needs. In essence, nuclear physics is an important component of America's past, a requisite item of our present, and an inevitable necessity for future growth and success, independent of all international energy sources. Unit Format: The following unit will take no more than two weeks to teach on block schedule (90 minute periods), or three weeks on a standard schedule (55 minute periods) Part I: History of the Manhattan Project (Block: 1 - 2 days) (Standard 2 - 3 days) Day 1: You will use computer laptop carts with students. Separate students into groups of 2-3. Assign each group to research one of the following topics from the list below: They must research and prepare an overhead acetate: Students will only be given 25 - 30 minutes for research and 10 minutes to write the information on acetate that they will present to the class. The other students must take notes from each group, as their homework assignment must be to create a 2-3 page essay based on information gained from the class (and only the class). The List is as follows: Fat Man and Little Boy Hanford Engineer Works; Hanford, Washington “Met Lab” Metallurgical Laboratory; Chicago, Illinois Oak Ridge, Tennessee The Secret City Los Alamos Laboratory 305 Test Pile and the “Queen Mary” Chemical Separations Building Chicago Pile #1 (CP-1), (CP-2, and CP-3), and the Instrument Shop K-25 Gaseous Diffusion Plant S-50 Thermal Diffusion Plant X-10 Graphite Reactor Y-12 Electromagnetic Plant Trinity Test Site DP Plutonium Processing Site Cockroft-Walton Machines and the Cyclotron Particle Accelerators and Van de Graff Generators Centrifuges and Electromagnetic Separation Gaseous Diffusion and Liquid-Thermal Diffusion Following student presentation, the teacher will need to help summarize the information given. This can be done with a flow chart, timeline, outline etc… 1 Day 2: The second day of history is a repeat of the first, only this time, the focus is on people and the science. The students will work under the same parameters as day 1, in new groups. (You will use computer laptop carts with students. Separate students into groups of 2-3. Assign each group to research one of the following topics from the list below: They must research and prepare an overhead acetate: Students will only be given 25 - 30 minutes for research and 10 minutes to write the information on acetate that they will present to the class. Students will write their notes on acetate and create a 2-3 page paper for their homework of the work presented in class, and only in class. The List is as follows: (Students need information on these people as scientists, their discoveries, not biographical birth and death date, degrees earned, marriages and children etc…), however, if they died of cancer etc… this may be important… Albert Einstein and E = mc2 Vannevar Bush and Arthur H. Compton James B Conant and Col. Leslie Richard Groves Franklin D. Roosevelt and Harry S. Truman Antoine Bequerel and James Chadwick Marie and Pierre Curie Enrico Fermi and Klaus Fuch Theodore Hall and Ernest O. Lawrence Lise Meitner, Otto Hahn, and Fritz Strassman J. Robert Oppenheimer and Glenn T. Seaborg Enola Gay and Project SilverPlate Neils Bohr and Josph C. Carter Richard Feyman and Leo Szilard Eugene Wigner and Phillip Morrison Felix Bloch and James Franck James Chadwick and Emilio Segre Edward Teller and Gustav Hertz Following student presentation, the teacher will need to help summarize the information given. This can be done with a flow chart, timeline, outline etc… Enrichment: If time allows there are a number of video and DVD’s available regarding the history of the atomic bomb, the Secret City, Graphite reactor and Y-12. to show the students for a real black and white historical perspective. 2 Part II: The Basic Science of Nuclear Physics (Block: 2 - 3 days) (Standard 3 - 4 days) Day 3: This is mostly a review of prior information learned. (students will need a calculator and graph paper- preferably scientific) Review: Structure of the Atom, Historical reference to discovery of proton, neutron, electron, and nucleus with special emphasis of Rutherfords Gold Foil Experiment, charged particles, and empty space filled with fields of energy. The Periodic Table: Atomic number, Average Atomic Mass, Isotopes, Mass Number and determination of protons, neutrons and electrons in a neutral atom. (Students will begin, but not complete in class a table regarding all of these for each element. They will complete the table for all elements for homework and create a graph with number of protons on the x axis and number of neutrons on the y axis. The next day, they will also draw a line of slope 1 where the number of protons equal the number of neutrons. This will lead to a discussion of stability and radioactive nuclei.) The fundamental forces of nature Gravity, electromagnetism, strong and weak nuclear forces with special attention given to the electromagnetic, strong and weak nuclear forces. Demonstration: Use small fish bowl with round bottom to represent the nucleus of an atom and marbles to represent the protons and neutrons. Allow all protons to be one color and all neutrons to be another color. Discuss electromagnetic repulsion of the neutrons in the nucleus, the strong force that must overcome those electric fields of positive charge, why the neutrons are so important to act as buffers and why the number of neutrons must be more than the number of protons. Students will complete the table and graph for homework as listed above. Day 4: Modeling Nuclear Decay Laboratory: Students will need to supply the following: 1 - 2 large bags of M&M’s 1 - 2 large bags of skittles (they will need more skittles than M&M’s) 1 - 2 large bags of individually wrapped candies or popped popcorn Students will model radioactive decay using M & M’s. Student groups of 2 – 3 should count out at least 1000 M&Ms, and record the total count. Starting the stopwatch as they turn the M&M’s one time in a shoe box and back down on a surface. At the beginning, all M&M’s were considered to be actively radioactive, now, only those that are lying with M & M’s up are radioactive. Separate the 3 radioactive (M’s up) from the non-radioactive (M’s down) or decayed M&M’s. Record these in a table. For every M&M that has decayed, place 3 skittles back and 2 wrapped candies or 2 pieces of popped corn in the mix. (Record the number of skittles and the wrapped candy or popped corn in a column on the table)The skittles represent a radioactive daughter nucleus that will also now be radioactive. The pieces of wrapped candy or kernels of popcorn model the large amount of stable non-radioactive atoms produced in a decay series. These final candy or popcorn material model those atoms produced by radioactive decay that would be less in mass but larger in number of atoms.The Stop the stopwatch and record this time. Students need only need to record one time for graphing purposes in this modeling exercise. Students will place all radioactive M&M’s and skittles back in the shoe box, turn once, and place them onto the table. Again, separating decayed from those still radioactive, and recording these in a data table. Again, 3 skittles replace every M&M that decays, however, as all of the skittles were originally radioactive when they were placed in the box, now we follow the same rules for them. If the S is up.it remains radioactive and will go back in the box, it it is down it has decayed and will be replaced by a final, stable candy. Now,5 pieces of wrapped candy or 5 popped kernels of popcorn replace every skittle that has decayed. Record all these numbers on a table. Continue to perform the decay process, recording the total number of each until all the M&M’s and Skittles have decayed to their final stable candy. Use the initial time taken through the first decay as a rounded whole number. This will be the time unit for the x axis of the student’s graph. Their homework assignment is to graph the number of M&M’s, Skittles, and final, stable candies, over an extended period of time, (ie…5 min. for each time interval). Students should have three separate connect the dot figures in different colors on their graph. What do all of these graphical figures represent? 4 Part III: A Little Advanced Theory on Nuclear Physics (Block: 1 day) (Standard 1 day) Day 5: Examples of Nuclear Decay Demonstrations: 1. Geiger Counter - If a Geiger counter is available, show students that it will work with the standard radioactive samples at your school. Have students bring in objects from home (ie…old pottery, old technology from their grandparents and great grandparents generation, stoneware painted placeware, etc…) Also show students that a smoke detector, which has an americium source will go Geiger active. 2. Use the Geiger counter to show the blocking of alpha and beta radiation, through hand, paper, concrete etc…. 3. Diffusion Cloud Chamber- A very simple diffusion cloud chamber can be made with a large clear plastic cup, dry ice and either alcohol or iodine crystals, and clear cellophane. Fill the bottom of the cup with dry ice, place the radioactive source on the dry ice, then place a few drops of dry ice or several iodine crystals in on top. Quickly place cellophane on top and observe. You will soon see the path of charged particles in the “clouds” of alcohol or iodine condensate. Video: Students now need to see one or more videos regarding radioactivity and radioactive decay. One of the best is actually put out by Disney called “Atom: A Closer Look.” 5 Part IV: Nuclear Problems (Balancing equations, Calculating Binding Energy, and the Half-Life equations) (Block: 3 - 4 days) (Standard 4 - 5 days) Day 6: Balancing Equations and Calculating Binding Energy Students will need a periodic table and a calculator. <see adjacent worksheets> Day 7: Calculating Binding Energy and Half-life Equations Students will need a periodic table and a calculator. <see adjacent worksheets> Day 8: Half-life Equations and Review of all Nuclear Math Students will need a periodic table and a calculator. <see adjacent worksheets> 6 Part V: Nuclear Applications (From Reactors and Medicine, to the Bomb) (Block: 1 day) (Standard 1 - 2 days) Day 9: You will use computer laptop carts with students. Separate students into groups of 2-3. Assign each group to research one of the following topics from the list below: They must research and prepare an overhead acetate: Students will only be given 25 - 30 minutes for research and 10 minutes to write the information on acetate that they will present to the class. The other students must take notes from each group, as their homework assignment must be to create a 2-3 page letter to a government official based on information gained from the class (and only the class). The List is as follows: Students should describe current of previous research at the facility, and any other relative information regarding it’s use and applications. Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) at ORNL Oak Ridge Electron Linear Accelerator Pulsed Neutron Sourse (ORELA) Holifield Radioactive Ion Bean Facility at ORNL Chernobyl (Where if any, do nuclear power plants exist in this state, and how old are they?) Large Hadron Collider (LHC) Conseil Européen pour la Recherche Nucléaire (CERN) Fermilab U.S. Nuclear Weapons Research, Development, Testing, and Production, and Naval Nuclear Propulsion Facilities at Brookings Facility Knolls Atomic Power Laboratory (KAPL) Lawrence Livermore National Laboratory (LLNL) Y-12 facility in Oak Ridge, Tennessee Los Alamos National Laboratory Radiation Therapy Medicine Design of Nuclear Weapons Radioactive Dating Nuclear Magnetic Resonance Imaging (NMR and MRI) Assignement: Students must now create a 2-3 page letter that they would write to any government official of their choosing. They can be for or against the use of nuclear research, energy, medicine, and or bomb proliferation etc... It is their choice, but they must choose a side and present valid arguments siting specific references that they learned. The letter must be in appropriate letter format, but does not actually have to be mailed to said government official. 7