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C HAPTER
11 TE Nuclear Chemistry
Chapter Outline
11.1 CHAPTER11: NUCLEARCHEMISTRY
11.1 Chapter 11: Nuclear Chemistry
Chapter Overview
Radioactivity is an atom’s ability to emit radiation from the nucleus. Many elements have radioactive isotopes and some elements have only radioactive isotopes. Nuclei of radioactive isotopes are unstable and undergo radioactive decay, in which they emit particles and/or energy and change to different elements. The rate of decay varies by element and is measured by the half-life. Nuclear reactions include nuclear fission and nuclear fusion. Both release huge amounts of energy. Einstein’s equation, E = mc2, explains why.
Online Resources
See the following Web sites for appropriate laboratory activities:
Have pairs of students do the radioactive decay and half-life lab at the following URL. It is based on a hands-on simulation of radioactive decay using pennies in a shoebox. From the class data, students will be able to make several important inferences about the rate of decay of radioactive elements.
• http://www.middleschoolscience.com/halflife.pdf
The nuclear fission simulation lab at the URL below is an award-winning inquiry lab. It is based on the nuclear fission simulation at the same URL.
• http://phet.colorado.edu/en/contributions/view/3273
This lab activity explains nuclear fusion and how radiation is generated by stars, using marshmallows as a model.
Students will explore cosmic radiation and where it comes from, and how the elements in the universe are generated.
The PDF contains step-by-step instructions, photos, presentation tips, links to background information, and a printable periodic table of the elements.
• http://nightsky.jpl.nasa.gov/docs/SNNuclearFusion.pdf These Web sites may also be helpful:
This document from NASA provides a detailed introduction to radiation and several related activities for middle school students. The focus is on the impact of radiation on living things.
• http://www.nasa.gov/pdf/284277main_Radiation_MS.pdf
At the following URL, you can find background readings and several activities on nuclear reactions and nuclear energy that were developed specifically for middle school students.
• http://www.uraweb.org/reports/skoog.pdf
The U.S. Department of Energy’s Booklet “The Harnessed Atom” is a comprehensive middle school teacher’s kit on nuclear energy. It includes many readings and review exercises that are germane to this chapter in the FlexBook®
resource. The PDF document can be found at this URL:http://www.osti.gov/speeches/doene0072.pdf .
11.1. Chapter 11: Nuclear Chemistry www.ck12.org
Pacing the Lessons
T
ABLE11.1:
Pacing the LessonsLesson Class Period(s) (60 min)
11.1 Radioactivity 1.5
11.2 Radioactive Decay 2.0
11.3 Nuclear Energy 2.0
11.2 Lesson 11.1 Radioactivity
Key Concept
Radioactivity is the ability of an atom to emit radiation from the nucleus. Many elements have one or more radioactive isotopes, and elements with more than 83 protons have only radioactive isotopes. Harmless background radiation comes from many sources such as cosmic rays. Radon and some other natural sources of radiation are harmful. Radiation has several uses, including uses in medicine.
Standards
• SCI.CA.8.PS.7.b
• NSES.5-8.F.1.7
• AAAS.6-8.1.A.2; AAAS.6-8.6.E.6
Lesson Objectives
• Explain radioactivity and how it was discovered.
• Describe sources, dangers, and uses of radiation.
Lesson Vocabulary
• radiation:particles and/or energy emitted by the nucleus of a radioisotope or an accelerating particle
• radioactivity:ability of an atom to emit charged particles and energy from the nucleus
• radioisotope:radioactive isotope, or isotope that emits radiation from its nucleus
Teaching Strategies
Introducing the Lesson
Before students delve into nuclear reactions in this chapter, help refresh their knowledge of subatomic particles and isotopes. Play the well-done music video “Parts of an Atom Song” at the URL below. It was created by a sixth-grade science teacher for his students, using catchy music by the popular band Maroon 5.
• http://www.youtube.com/watch?v=O5iaw5WNuB0
11.2. Lesson 11.1 Radioactivity www.ck12.org Using Visuals
Have students use the periodic table in the FlexBook® lesson to identify all of the radioactive elements (atomic numbers 84–118) as well as the naturally occurring radioactive elements (atomic numbers 84–92). Point out that many elements with lower atomic numbers also have radioactive isotopes. Ask each student to select a number from 1 to 83 and find the element with that atomic number in the periodic table. Then have them suggest a possible radioactive isotope for that element. They can see if they are correct with an interactive elements site such as this one:http://www.webelements.com/ .
Differentiated Instruction
After students read the opening paragraph of the FlexBook® chapter, ask them to make a KWL chart to guide their reading of the first lesson. A sample chart has been started below (seeTable11.2). They should fill in the Know and Want to Know columns before they read the lesson and the Learned column as they read or complete the lesson.
T
ABLE11.2:
KWL ChartKnow Want to Know Learned
Example: Elements cannot change to other elements in chemical reac- tions.
Example: How can some elements change to other elements?
Example: Some elements can change to other elements when their nuclei give off particles and energy.
Enrichment
Suggest to students that they learn more about the research on radioactivity of Antoine Henri Becquerel and the Curies. They can start with the URLs below. Ask them to create a PowerPoint presentation to share what they learn with the rest of the class.
• http://www.nobelprize.org/nobel_prizes/physics/laureates/1903/becquerel-bio.html
• http://www.aboutnuclear.org/view.cgi?fC=History,Hall_of_Fame,Henri_Becquerel
• http://www.physics.isu.edu/radinf/cuire.htm
• http://www.nobelprize.org/nobel_prizes/physics/articles/curie/
• http://www.pbs.org/wnet/hawking/cosmostar/html/cstars_curies.html
Science Inquiry
Have students do the “Personal Radiation” activity (pages 36–39) at the following URL. In the activity, students can calculate the amount of natural radiation to which they are exposed and then formulate a hypothesis as to whether they need to modify their environment or behavior.
• http://www.uraweb.org/reports/skoog.pdf Common Misconceptions
Misconceptions about radioactivity and radiation are common. The following URL identifies several of them and explains why they are incorrect. For each misconception, the Web site also offers detailed tutorials, simulations, or other interactive media that you and your students can access.
• http://www.furryelephant.com/content/radioactivity/teaching-learning/radioactivity-misconceptions/
Reinforce and Review
Lesson Worksheets
Copy and distribute the lesson worksheets in theCK-12 Physical Science for Middle School Workbook. Ask students to complete the worksheets alone or in pairs to reinforce lesson content.
Lesson Review Questions
Have students answer the Review Questions listed at the end of the lesson in the FlexBook® student edition.
Lesson Quiz
Check students’ mastery of the lesson with Lesson 11.1 Quiz inCK-12 Physical Science for Middle School Quizzes and Tests.
Points to Consider
In this lesson, you read that unstable nuclei emit particles and energy.
• What type of particles do you think unstable nuclei emit?
• What form of energy do you think these nuclei give off?
11.3. Lesson 11.2 Radioactive Decay www.ck12.org
11.3 Lesson 11.2 Radioactive Decay
Key Concept
Radioactive decay is the process in which unstable nuclei emit particles and energy and change to different elements.
Types of decay include alpha, beta, and gamma decay. They differ in what is emitted, how far it can travel, and what it can penetrate. The rate of radioactive decay, measured by the half-life, varies from one radioisotope to another.
Standards
• AAAS.6-8.4.D.2; AAAS.6-8.4.F.9
Lesson Objectives
• Identify three types of radioactive decay.
• Define the half-life of a radioisotope.
• Explain radioactive dating.
Lesson Vocabulary
• half-life:length of time it takes for half of a given amount of a radioisotope to decay
• radioactive dating: method of determining the age of fossils or rocks that is based on the rate of decay of radioisotopes
• radioactive decay: process in which the unstable nucleus of a radioisotope becomes stable by emitting charged particles and energy and changing to another element
Teaching Strategies
Introducing the Lesson
Introduce radioactive decay by probing students’ understandings of the termdecay. Play a word association game, using decayas the prompt. Call on each student in turn to say the first word that comes to mind when they hear the worddecay. (Possible responses might include rot, break down, spoil and fall apart.) When no new responses are forthcoming, explain to the class that they will learn how unstable nuclei decay when they read this lesson.
Challenge them to predict what decay means in this context.
Activity
Use the activity at the URL below to introduce the three types of radioactive decay. With the activity, students can explore how decay leads to the transmutation of elements. It requires them to use mathematical reasoning and graphing skills and will give them an understanding of radioactive decay at the conceptual level. The URL provides all necessary worksheets and other materials for students as well as teacher notes and sample answers.
• http://www.nuclearscienceweek.org/images/uploads/Alphas-Betas-Gammas-Oh-My.pdf Differentiated Instruction
Work with students to make a compare/contrast table for alpha, beta, and gamma decay. A sample is shown in the Table11.3.
T
ABLE11.3:
Compare/Contrast Table for DecayType of Decay What Is Emitted? Is a New Element Produced?
Alpha alpha particle (2 protons + 2 neu-
trons) & energy
yes
Beta beta particle (1 electron) & energy yes
Gamma energy (only) no
Enrichment
Ask one or more students to make a Jeopardy quiz game on lesson content. First, they should prepare a list of at least 20 answers that require contestants to generate the correct questions. Here are two possible examples:
Answer: Tiny particle emitted by uranium-238 when it changes to thorium-234 Question: What is an alpha particle?
Answer: Rays of energy that can be stopped only be several meters of concrete Question: What are gamma rays?
After the students have created the list of answers (including the number of points for each one based on difficulty), have them lead the class in playing the game. Contestants can be individual students, partners, or small groups. If you wish, you can have the students use the Flash Jeopardy game generator at this URL below to create an online version of the game:http://www.superteachertools.com/jeopardy/ .
Science Inquiry
Assign the half-life and radioactive dating game lab at the first URL below. The lab worksheet guides students in using the simulation at the second URL below. In the lab, students investigate the half-lives of carbon-14 and uranium-238 and use radioactive dating to estimate the ages of virtual fossils and rocks. In the analysis section, students apply the concepts of half-life and radioactive dating to solve additional problems.
• http://phet.colorado.edu/en/contributions/view/3534
• http://phet.colorado.edu/en/simulation/radioactive-dating-game
11.3. Lesson 11.2 Radioactive Decay www.ck12.org Common Misconceptions
The URL below provides an alternative radioactive dating activity to the one described just above. In this “Date a Rock!” activity, students use simulated rock samples, each one containing a different proportion of a parent radioisotope and its daughter product. By counting atoms and using knowledge of the half-life of the parent radioisotope, students estimate the ages of the rock samples. The Web site includes a materials list, overhead transparencies, teaching strategy, pre- and post-lab assessments, extensions, and other resources.
• http://www.indiana.edu/~ensiweb/lessons/date.les.html Life Science Connection
Discuss the importance of radioactive dating to our understanding of how living things have evolved. The URL below provides additional information that you may want to share with students.
• http://www.c14dating.com/int.html
Reinforce and Review
Lesson Worksheets
Copy and distribute the lesson worksheets in theCK-12 Physical Science for Middle School Workbook. Ask students to complete the worksheets alone or in pairs to reinforce lesson content.
Lesson Review Questions
Have students answer the Review Questions listed at the end of the lesson in the FlexBook® student edition.
Lesson Quiz
Check students’ mastery of the lesson with Lesson 11.2 Quiz inCK-12 Physical Science for Middle School Quizzes and Tests.
Points to Consider
Radioactive decay releases energy. Other types of nuclear reactions also release energy.
• What other types of reactions might the nucleus undergo?
• What might be the pros and cons of using nuclear reactions for energy?
11.4 Lesson 11.3 Nuclear Energy
Key Concept
Nuclear fission is the splitting of the nucleus of an atom into two smaller nuclei. This releases a great deal of energy, which can be used to generate electricity. Nuclear fusion is the fusing of two or more smaller nuclei to form a single, larger nucleus. This releases even more energy than fission, but the energy of fusion has not yet been harnessed for generating electricity. Einstein’s equation,E=mc2, explains why a tiny amount of mass changes to such large amounts of energy during nuclear reactions.
Standards
• MCR.6-8.SCI.9.6, 11
• NSES.5-8.B.3.5; NSES.5-8.F.3.2
• AAAS.6-8.1.A.3; AAAS.6-8.3.C.1, 3, 5, 7; AAAS.6-8.4.B.9, 12; AAAS.6-8.8.C.2, 4, 10, 11; AAAS.6- 8.11.C.3; AAAS.6-8.12.D.6, 11
Lesson Objectives
• Describe nuclear fission and how it is used for energy.
• Describe nuclear fusion and challenges to its use for energy.
• Relate nuclear energy to Einstein’s equation,E=mc2.
Lesson Vocabulary
• nuclear energy:energy released in a nuclear reaction (nuclear fission or nuclear fusion)
• nuclear fission:splitting of the nucleus of an atom into two smaller nuclei
• nuclear fusion:fusing of two or more small nuclei to form a single, larger nucleus
Teaching Strategies
Introducing the Lesson
Introduce nuclear reactions with the student-created video at the URL below. It demonstrates a nuclear chain reaction with mousetraps and ping-pong balls and is sure to generate student interest in the topic. Tell students they will learn the science behind the demonstration when they read this lesson.
11.4. Lesson 11.3 Nuclear Energy www.ck12.org
• http://www.youtube.com/watch?v=0v8i4v1mieU Discussion
Discuss the pros and cons of using nuclear energy to produce electricity. Compare it to the use of fossil fuels as well as to alternative energy resources such as solar and wind energy. After the discussion, organize a debate about the use of nuclear energy as an alternative to fossil fuels. Ask a few volunteers to choose sides and then debate the issue in front of the class.
Activity
Students can use the excellent simulations at the URL below to explore nuclear fission. In the activity, they can start a nuclear chain reaction and use control rods to limit a nuclear chain reaction in a power plant. Teaching materials are also provided at the Web site.
• http://phet.colorado.edu/en/simulation/nuclear-fission Building Science Skills
Have students watch and interpret the animated model of nuclear fusion at the following URL. Ask them to identify what the gray and red balls represent in the model (gray balls = neutrons, red balls = protons). Also ask them to identify the reactants and products in the reaction. (The reactants are deuterium and tritium, and the products are helium and a neutron.)
• http://www.atomicarchive.com/Movies/Movie5.shtml Differentiated Instruction
Partner any English language learners and less proficient readers with other students, and have partners create a Venn diagram comparing and contrasting nuclear fission and nuclear fusion. The area of overlap might include “nuclear reaction” and “releases a lot of energy.” The area limited to fission might include “one large nucleus splits into two smaller nuclei.” The area limited to fusion might include “two small nuclei join into one large nucleus.”
Enrichment
Some students might be interested to learn how nuclear fission was discovered. Have them read and listen to the fascinating first-person account of the story at the URL below. The article is liberally interspersed with recorded statements by some of the main players, including Einstein, Curie, and Meitner. The scientists describe the break- throughs as they actually happened.
• http://www.aip.org/history/mod/fission/fission1/01.html Science Inquiry
Students can explore nuclear reactors by making a model of a nuclear reactor with Activity 2 on page 17 in the following PDF document. In the activity, students use simple materials to make their model and then compare the parts of their model to the parts of a real nuclear reactor (Three Mile Island reactor). They will also research and describe the basic processes that take place in a nuclear reactor.
• http://www.efmr.org/edu/nuclear2009.pdf
Real-World Connections
Have students find nuclear power plants in their state or region of the country at the URL below. (They should click on the National Map and then plot all the nuclear power plants.) The map will distinguish operating, proposed, and closed nuclear facilities. Suggest that students do a Web quest to learn more about the nuclear power plant closest to their location.
• http://www.energyjustice.net/map/
Reinforce and Review
Lesson Worksheets
Copy and distribute the lesson worksheets in theCK-12 Physical Science for Middle School Workbook. Ask students to complete the worksheets alone or in pairs to reinforce lesson content.
Lesson Review Questions
Have students answer the Review Questions listed at the end of the lesson in the FlexBook® student edition.
Lesson Quiz
Check students’ mastery of the lesson with Lesson 11.3 Quiz inCK-12 Physical Science for Middle School Quizzes and Tests.
Points to Consider
Einstein’s equation is part of a larger theory called the theory of relativity. It is concerned with concepts such as motion and forces as well as mass and energy. Motion and forces are the focus of succeeding chapters.
• Based on your real-world experiences, how would you define motion?
• Forces include gravity and friction. How might these forces be related to motion?
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C HAPTER
12 TE Motion
Chapter Outline
12.1 CHAPTER12: MOTION