Unit Plan: Nuclear ChemistryThis will be the last unit covered during the second semester of high school chemistry. This unitshould cover approximately two to three weeks worth of lessons and labs while the researchproject will continue through to the last week of class so that students may present theirfindings in a round table discussion.IntroductionThere are three major nuclear reactions that students will be able to compare and contrast:fission, fusion, and naturally occurring radioactive decay. Each is discussed in the worlds of thevery small and very big since atomic energy composition through astronomy will be topics ofconversation during the unit. They will study how isotopes play a large role in radioactive decaydue to their instability and spontaneous particle radiation. Current events and politics will bediscussed with the addition of a study on uranium and plutonium development in the world asit relates to power struggles over tremendous amounts of energy (i.e. weapons, power plants,medical technology).Additionally the historical aspect of nuclear chemistry will de discuss in detail so that studentsmay understand how scientist came to their conclusions concerning the makeup up atoms,their decay through particle ejection, and the process of determining a species’ age throughhalf‐life and carbon dating.Students will be able to negotiate a reasonable opinion about the dangers of controlling fusionreactions as it relates to the energies equal to that of our parent star. They will also have theopportunity to discuss their thoughts on the importance of scientific research with fissionreactions, particle accelerators, and theoretical sciences.Lastly students will be required to conduct a research project that reflects their scientificliteracy of nuclear chemistry. This project will require students to read and research textsrelated to a selected topic, write a formal paper on their findings and opinions, and lastlycommunicate their data to the class in the form of a presentation. This final project will beused in lieu of a unit test.
Unit Objectives Describe the characteristics of alpha, beta, and gamma radiation Balance nuclear equations of the radioactive decay process Compare fusion and fission reactions Understand the formula Use half‐life information to determine lifetime equations Become familiar with the concept of carbon dating Utilize their conceptual knowledge of nuclear chemistry to conduct academic researchand its relation to atomic energyT.E.K.S. 112.35—High School Chemistry(c) Knowledge and skills(12) Science concepts. The student understands the basic processes of nuclear chemistry.The student is expected to:(A) describe the characteristics of alpha, beta, and gamma radiation;(B) describe radioactive decay process in terms of balanced nuclear equations; and(C) compare fission and fusion reactions.Background1. The nucleus of an atom is composed of protons and neutrons which are equal in mass andcomparatively more massive than electrons therefore contain more energy. Isotopes ofelements contain different numbers of neutrons in the nucleus and may be either stable orunstable. The decay of unstable isotopes is a natural and spontaneous phenomenon.2. The number of protons in the nucleus solely determines the identity of any element. Allprotons have a positive charge yet are held together very tightly in the core of atoms. This isbecause the strong nuclear force overpowers the electrical charge of the particles which wouldhave them fly apart.3. Nuclear reactions convert a fraction of their mass into vast amounts of energy by eithersplitting or fusing nuclei with enormous speed.4. Half‐life refers to the amount of time it takes for one half of a sample to completely decay.This process can be determined with a mathematical equation and is used in carbon dating.
Part One: Nuclear DecayDaniels, Zemelman & Steinek—Content‐Area WritingA powerful idea from this book is that students gain more from writing than any other task sincelearning is harnessed by having students put their ideas into their own words. This can be done in manyways but the most useful strategy in a classroom is to have students take moments to write out theirthoughts spontaneously so that their first impressions can be used for self assessment. I students areallowed to write and discuss in small groups then they may share what they know and help each otherdefine meaning in the lessons. Brainstorming, illustrating, and on‐the‐spot solo writing are good toolsfor preparing students to bring together their thoughts for future academic writing.A. As an introduction to the unit students will be given an assignment to read (See Introductionto Nuclear Chemistry) prior to the first class lesson. This introduction will give students somebackground on the unit and introduce them to the language used throughout.During the first class meeting students will be introduced to concepts of nuclear chemistry suchas particle radiation, their relative energies, and properties. A collection of projected slides willsupport visual learning in addition to defining terms of the unit.Introduced in this first class are:1. Alpha, beta, and gamma radiation including their relative charges, energies andcomposition2. Isotopes and their rates of instability which affect decay3. Writing and solving balanced nuclear equationsSlides 1‐8 will be used to graphically represent the material of the first lesson. For step #3examples of nuclear reaction equations will be demonstrated on the board while studentspractice the steps of writing and balancing in their notebooks. The following website may beused to practice these types of equations either in class or at nit1NuclearEquations.htmB. Following the first lesson students will conduct their first assignment in class. This is a freewrite where students must continuously write for five minutes in any form they choose. It maybe fictitious, poetic, or personal but should include terms related to what they have learnedfrom their pre‐lesson reading. Students will be given a blank sheet of paper at the open of classand asked to write. They may use the introduction article for this assignment but should writein their own words.
1. Examples of writings may include a story, statements of what they have learned, and/orquestions that they may have on the topic.2. Students will discuss what they have written in small groups to come up with tenconcepts or terms dealing with nuclear chemistry.3. On the opposite side of their sheet of paper they will create a graphic organizer basedon these ten ideas.C. Simulating radioactive decayPopping popcorn in class is an excellent way of demonstrating the spontaneity and irreversiblechange associated with radioactive decay. In the front of the classroom the teacher will have ahot plate with popcorn kernels in oil slowly heating while an introduction is given on radioactivedecay of atoms. Noted is that while you may predict which kernels will pop first there is nocertain method for establishing what order they will pop and identifying which will not pop.Additionally it should be mentioned that once the kernel has popped (decayed) it cannot returnto its primary state. While the kernels are heated students will be prompted with the following: Predict which corn kernels will pop first. What are variables that control whether a kernel of corn will pop? What happens to the kernel of corn when it does pop? Can it go back to the way it wasbefore it popped?D. Solving nuclear equations reviewStudents will be given a worksheet which contains problems for balancing nuclear equations,predicting isotopes present during radioactive decay, and writing balanced equations based onword problems. Students will be guided by the teacher through the left hand column of theworksheet for questions one and two (not the word problems). Students will be given time inclass to complete the worksheet or turned in the next day for a homework grade.Students will be encouraged to work in small groups so that those who understand the conceptmay help students who are having trouble understanding the steps of the process.E. Understanding of half‐lifeRadioactive decay occurs at a certain rate and depends on the stability of the species’ isotopeand the environment from which it is exposed. Students will be expected to understand that
half‐life refers to not only the process of decay but also that it is the amount of time that ittakes for a sample to decrease by half through decay. Half‐life refers to the time it takes for half of a sample of atoms decays Half‐life describes whole entities therefore there cannot be a moment where half of anatom exists Half‐life is defined as a probability rate therefore experimentally it will not always becompletely accurate While this is a probability, the large number of atoms in a sample will produce anaverage decay sequence equal to that where probability can be ignored Once a sample begins the decay process it cannot reverseE. Simulation labIn order for students to comprehend the process of half‐life they will conduct an experimentwhere they may simulate the process of decay with the use of pennies. Students will have theopportunity to fully grasp the concept by enacting the reaction rate, gathering data based ontheir findings and plotting their on a graph.Refer to Nuclear Chemistry Lab: The Radioactive “Decay of Pennium”In this experiment students will review the probability rate discussed during the popcorndemonstration to focus their learning on decayed and non‐decayed atoms in a sample.Students will be given 100 pennies, a cup with a lid and lab instructions with which they mayplot their data. They will be asked to systematically shake the sealed cup with pennies, pourthem onto a hard surface and remove pennies which are tails up (the decayed atoms ofpennium). Recording their figures and repeating these steps until all the pennies have“decayed” students will have a greater understanding of the decay process. Students will thenplot their data on a table to reveal that the rate quotient is not a straight line but rather a curveshowing that the increments decrease but a rate of approximately half with each successiveturn. Students will work in groups and submit individual data tables, plots, and summativequestions the following day.F. During the final part of this lesson students will be involved in a free write session that is usedto elaborate their knowledge on the concept of half‐life and particle decay. They will be
expected to use terminology from the unit to depict their understanding of how atomicstructure leads to decaying material and what scientist may learn from samples that havedecayed.G. Assessment—students will take a quiz on half‐life and nuclear reaction equationsSee Half‐life QUIZ
Part Two: Nuclear Reactions and Subatomic ParticlesDeVoss, Eidman & Hicks— Because Digital Writing MattersThe digital age has forever changed the method of teaching because it allows other to create valuablelearning tools for students and teachers. The use of video, web pages, and internet distribution can helpstudents to focus their learning by developing different perspectives of what lessons can become.Videos are a helpful means of learning in science as many concepts are abstract an unobservable due totheir occurrence at the microscopic level. Learning about atoms, subatomic particles, and chemicalreactions can make a profound difference in visualizing inconceivable concepts.Robb—Multiple TextsThe use of multiple texts is a very convenient tool when learning difficult subject matter. Multiple textsoffer many different perspectives on subjects and may better explain concepts to students. The same asthere are various authors writing about the same subject, there are various brain types reading them,therefore some connections may be made where others may not. From personal experience I can saythat I learned chemistry not from a chemistry book; instead I learned with the aid of teacher handoutsand endless Google searches. The different perspectives helped to funnel in material and triangulateinformation across many genres.A. Review of particle decay and fission and fusion reactionsSlides from the PowerPoint presentation will follow this demonstration as students will reviewconcepts particle decay, briefly discuss carbon‐14 decay, and a brief on to fission and fusionreactions.Once the review is covered students will engage in a lesson on fission and fusion reactions withthe aid of web articles and group discussions. The guiding questions for this lesson are asfollows: What are nuclear fission and fusion? How are they alike and how are they different? How is the fission process used in nuclear reactors?Students will use their existing knowledge of nuclear chemistry to create a KWL chart and workin small groups in order to create a compiled list of concepts. These concepts will be discussedas a class toward the end of their discussion and recorded on the board so that student maycomprehend the basics of these reactions. Next students will be asked to read articles onfission and fusion reactions where they will make predictions prior to the read and correctionsto those predictions afterward. Third, students will complete a formative assessment of thematerial by creating a Venn diagram that compares and contrasts both reactions. Fourth,
demonstrate the structure and working process of nuclear reactors with an online media toolwhich uses animations to grant visual understanding of nuclear power at work. If students haveaccess to a computer lab with online access then it is advisable to allow students to manipulatethe tool. Once this sequence is complete students will be asked to write in their notebooks asummary of the concepts presented in this lesson and pose questions that still remain as theywill work in small groups to define their understand