DOCSLIB.ORG

Fusion Or Fission (Lexile 1020L)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Fusion Or Fission (Lexile 1020L) C.12ABC: Nuclear Chemistry Atomic Structure and Nuclear Chemistry Fusion or Fission (Lexile 1020L) 1 Nuclear reactions can generate a lot of energy. However, not all nuclear reactions are the same. There are two very distinct types of nuclear reactions—fusion reactions and fission reactions. What are the differences and similarities between nuclear fission and nuclear fusion? As you have learned, all atoms are made of subatomic particles called protons, neutrons, and electrons. In the simplest terms, nuclear fission occurs when large, unstable atoms split into smaller atoms to achieve a more stable state. Nuclear fusion is the opposite of fission. Fusion occurs when smaller atoms bind together to form a larger, more stable atom. In both cases, the reaction occurs to bring the atom to a more stable state by a reduction of potential energy. 2 Nuclear fission reactions occur when the nucleus of an atom is split into fragments. When this occurs, smaller fragments are created. Most often, the result is two fragments of relatively equal mass. How is this energy created? You can compare the mass of the starting atom and the masses of the final products. You will find that the mass of the final products is less than the mass of the starting atom. Yes, in this type of nuclear reaction, mass is lost! This means that matter is lost. This loss of matter is known as the mass defect. Remember, the law of conservation of mass is for non-nuclear changes. Nuclear reactions are described by conservation of mass-energy. The small amount of lost mass is converted directly into large amounts of energy. The energy created from this reaction can be used to generate electricity in power plants or for the huge explosions of atomic bombs. 3 One type of atom used for fission reactions is an unstable isotope of uranium known as uranium-235. The stable isotope is uranium-238. In order for this reaction to occur, a neutron must collide with the uranium-235 nucleus, creating uranium-236. This collision creates enough energy to split the newly-formed nucleus into smaller nuclei. A huge amount of energy is released in the process. As the nucleus splits and releases energy, more neutrons are produced. These may collide with another uranium-235 nuclei, causing it to undergo fission. This will create more energy and produce even more neutrons. The reaction will become something called a chain reaction if enough neutrons are produced during collisions 1 C.12ABC: Nuclear Chemistry Atomic Structure and Nuclear Chemistry to keep the reaction going. The minimum amount of material that is needed for the reaction to keep going is called the critical mass. The trouble with fission reactions is that radiation and nuclear waste products are created in the process. This is a problem, as many nuclear power plants use fission to produce energy, producing a lot of radioactive byproducts as a result. 4 Conversely, in fusion reactions, the nuclei from atoms with low atomic weights combine to create heavier nuclei. This reaction does not require neutrons in order to occur. Two light nuclei must collide with a great deal of energy. Fusion reactions require extremely high heat. In fact, the heat required can exceed several million degrees Celsius (yes, several million!) To put these types of temperatures in perspective, the temperature at the surface of the sun is around 5,600 ºC. Meanwhile, the temperature near the core of the sun is calculated to be around 15 million ºC. The temperature of the sun stated here should give you a hint of a nuclear reaction that you can observe. The sun is a product of an ongoing fusion reaction that has been occurring for billions of years. 5 Why is such high heat required for these reactions? Remember, the protons of atoms are all positively charged. In order to combine atoms, the repulsion of the positive protons of the combining atoms must first be overcome. Extremely high heat gives the nuclei the kinetic energy needed to overcome the repulsion. And as shown with the sun, fusion reactions are also very exothermic. Therefore, fusion reactions have the capability of producing more energy than is required to initiate the reaction. This creates a self-sustaining reaction that holds great promise for energy production. A fusion reaction will sometimes begin with a fission reaction to get it started. In the right conditions, it can sustain itself, once started. One of the benefits of fusion reactions is that there are no radioactive byproducts. On earth, fusion reactions result in the element helium. Heavier elements, like beryllium or carbon, are produced by fusion in stars. Hydrogen bombs are produced by fusion reactions in which several isotopes of the element hydrogen are combined to produce helium. 6 How can you remember the difference between these two types of nuclear reactions? Think in terms of vocabulary that you may already know. A fissure is a crack or opening that can appear on the surface of earth. It is a separation. A fission reaction will therefore "separate" an unstable atom into parts. A fusion reaction will "fuse" two atoms together. 2 C.12ABC: Nuclear Chemistry Atomic Structure and Nuclear Chemistry 1 There are two distinct types of nuclear reactions. One is a fusion reaction, and one is a fission reaction. In which reaction is the nucleus of an atom split into two or more atoms? A Fusion reactions B Fission reactions C Both nuclear reactions D Neither nuclear reaction 2 In order for fission reactions to be successful, they must be self- perpetuating, meaning they must be able to keep themselves going. What do you call the minimum amount of material that is needed for the reaction to keep going? A The isotope B The mass defect C The critical mass D The neutron 3 Our sun is a star that is fueled by a specific type of nuclear reaction. Which type of nuclear reaction is this? A Fusion B Solar C Fission D Radioactive 3 C.12ABC: Nuclear Chemistry Atomic Structure and Nuclear Chemistry 4 Why is the fusion reaction not currently used to produce energy, especially as it is a "clean" form of energy that does not create radioactive or nuclear byproducts? A There are currently not enough fuels for fusion reactions. B Fusion reactions are highly endothermic, making them dangerous. C Fusion reactions do not yet produce enough energy. D The heat it takes to start a fusion reaction is too high to contain. 5 Fission reactions are currently used to provide energy for many different sources. Where does the energy produced during the reaction come from? A From the mass lost during the reaction, or the mass defect B From the mass created during the reaction, or the mass increase C From the critical mass of the reaction D From the protons created during the reaction 4.
Load more

Recommended publications
  • Uranium (Nuclear)
    Uranium (Nuclear) Uranium at a Glance, 2016 Classification: Major Uses: What Is Uranium? nonrenewable electricity Uranium is a naturally occurring radioactive element, that is very hard U.S. Energy Consumption: U.S. Energy Production: and heavy and is classified as a metal. It is also one of the few elements 8.427 Q 8.427 Q that is easily fissioned. It is the fuel used by nuclear power plants. 8.65% 10.01% Uranium was formed when the Earth was created and is found in rocks all over the world. Rocks that contain a lot of uranium are called uranium Lighter Atom Splits Element ore, or pitch-blende. Uranium, although abundant, is a nonrenewable energy source. Neutron Uranium Three isotopes of uranium are found in nature, uranium-234, 235 + Energy FISSION Neutron uranium-235, and uranium-238. These numbers refer to the number of Neutron neutrons and protons in each atom. Uranium-235 is the form commonly Lighter used for energy production because, unlike the other isotopes, the Element nucleus splits easily when bombarded by a neutron. During fission, the uranium-235 atom absorbs a bombarding neutron, causing its nucleus to split apart into two atoms of lighter mass. The first nuclear power plant came online in Shippingport, PA in 1957. At the same time, the fission reaction releases thermal and radiant Since then, the industry has experienced dramatic shifts in fortune. energy, as well as releasing more neutrons. The newly released neutrons Through the mid 1960s, government and industry experimented with go on to bombard other uranium atoms, and the process repeats itself demonstration and small commercial plants.
    [Show full text]
  • An Introduction to the IAEA Neutron-Gamma Atlas Ye Myint1, Sein Htoon2
    MM0900107 Jour. Myan. Aca<L Arts & Sa 2005 Vol. in. No. 3(i) Physics An Introduction to the IAEA Neutron-Gamma Atlas Ye Myint1, Sein Htoon2 Abstract NG-ATLAS is the abbreviation of Neutron-Gamma Atlas. Neutrons have proved to be especially effective in producing nuclear transformations, and gamma is the informer of nucleus. In nuclear physics, observable features or data are determined externally such as, energy, spin and cross section, where neutron and gamma plays dominant roles. (Neutron, gamma) (n,y) reactions of every isotope are vital importance for nuclear physicists. Introduction Inside the nucleus, protons and neutrons are simply two different states of a single particle, the nucleon. When neutron leaves the.nucleus, it is an unstable particle of half life 11.8 minutes, beta decay into proton. It is not feasible to describe beta decay without the references to Dirac 's hole theory; it is the memorandum for his hundred-birth day . The role of neutrons in nuclear physics is so high and its radiative capture by elements (neutron, gamma) reaction i.e, (n,y ) or NG-ATLAS is presented. The NG-Atlas. data file contains nuclear reaction cross section data of induced capture reaction for targets up to Z =96 . It comprises more than seven hundred isotopes, if the half lives are above half of a day. Cross sections are listed separately for ground , first and second excited states .And if the isomers have half life longer than 0.5 days , they are also include as targets .So the information includes a total of about one thousand reactions on different channels and the incident neutron energy ranging fromlO"5 eV to 20 MeV.
    [Show full text]
  • Fundamentals of Nuclear Power
    Fundamentals of Nuclear Power Juan S. Giraldo Douglas J. Gotham David G. Nderitu Paul V. Preckel Darla J. Mize State Utility Forecasting Group December 2012 Table of Contents List of Figures .................................................................................................................................. iii List of Tables ................................................................................................................................... iv Acronyms and Abbreviations ........................................................................................................... v Glossary ........................................................................................................................................... vi Foreword ........................................................................................................................................ vii 1. Overview ............................................................................................................................. 1 1.1 Current state of nuclear power generation in the U.S. ......................................... 1 1.2 Nuclear power around the world ........................................................................... 4 2. Nuclear Energy .................................................................................................................... 9 2.1 How nuclear power plants generate electricity ..................................................... 9 2.2 Radioactive decay .................................................................................................
    [Show full text]
  • Nuclear Chemistry Why? Nuclear Chemistry Is the Subdiscipline of Chemistry That Is Concerned with Changes in the Nucleus of Elements
    Nuclear Chemistry Why? Nuclear chemistry is the subdiscipline of chemistry that is concerned with changes in the nucleus of elements. These changes are the source of radioactivity and nuclear power. Since radioactivity is associated with nuclear power generation, the concomitant disposal of radioactive waste, and some medical procedures, everyone should have a fundamental understanding of radioactivity and nuclear transformations in order to evaluate and discuss these issues intelligently and objectively. Learning Objectives λ Identify how the concentration of radioactive material changes with time. λ Determine nuclear binding energies and the amount of energy released in a nuclear reaction. Success Criteria λ Determine the amount of radioactive material remaining after some period of time. λ Correctly use the relationship between energy and mass to calculate nuclear binding energies and the energy released in nuclear reactions. Resources Chemistry Matter and Change pp. 804-834 Chemistry the Central Science p 831-859 Prerequisites atoms and isotopes New Concepts nuclide, nucleon, radioactivity, α− β− γ−radiation, nuclear reaction equation, daughter nucleus, electron capture, positron, fission, fusion, rate of decay, decay constant, half-life, carbon-14 dating, nuclear binding energy Radioactivity Nucleons two subatomic particles that reside in the nucleus known as protons and neutrons Isotopes Differ in number of neutrons only. They are distinguished by their mass numbers. 233 92U Is Uranium with an atomic mass of 233 and atomic number of 92. The number of neutrons is found by subtraction of the two numbers nuclide applies to a nucleus with a specified number of protons and neutrons. Nuclei that are radioactive are radionuclides and the atoms containing these nuclei are radioisotopes.
    [Show full text]
  • Nuclear Reactions Fission Fusion
    Nuclear Reactions Fission Fusion Nuclear Reactions and the Transmutation of Elements A nuclear reaction takes place when a nucleus is struck by another nucleus or particle. Compare with chemical reactions ! If the original nucleus is transformed into another, this is called transmutation. a-induced Atmospheric reaction. 14 14 n-induced n 7N 6C p Deuterium production reaction. 16 15 2 n 8O 7 N 1H Note: natural “artificial” radioactivity Nuclear Reactions and the Transmutation of Elements Energy and momentum must be conserved in nuclear reactions. Generic reaction: The reaction energy, or Q-value, is the sum of the initial masses less the sum of the final masses, multiplied by c2: If Q is positive, the reaction is exothermic, and will occur no matter how small the initial kinetic energy is. If Q is negative, there is a minimum initial kinetic energy that must be available before the reaction can take place (endothermic). Chemistry: Arrhenius behaviour (barriers to reaction) Nuclear Reactions and the Transmutation of Elements A slow neutron reaction: is observed to occur even when very slow-moving neutrons (mass Mn = 1.0087 u) strike a boron atom at rest. 6 Analyze this problem for: vHe=9.30 x 10 m/s; Calculate the energy release Q-factor This energy must be liberated from the reactants. (verify that this is possible from the mass equations) Nuclear Reactions and the Transmutation of Elements Will the reaction “go”? Left: M(13-C) = 13.003355 Right: M(13-N) = 13.005739 M(1-H) = 1.007825 + M(n) = 14.014404 D(R-L)= 0.003224 u (931.5 MeV/u) = +3.00 MeV (endothermic) Hence bombarding by 2.0-MeV protons is insufficient 3.0 MeV is required since Q=-3.0 MeV (actually a bit more; for momentum conservation) Nuclear Reactions and the Transmutation of Elements Neutrons are very effective in nuclear reactions, as they have no charge and therefore are not repelled by the nucleus.
    [Show full text]
  • Chapter 14 NUCLEAR FUSION
    Chapter 14 NUCLEAR FUSION For the longer term, the National Energy Strategy looks to fusion energy as an important source of electricity-generating capacity. The Department of Energy will continue to pursue safe and environmentally sound approaches to fusion energy, pursuing both the magnetic confinement and the inertial confinement concepts for the foreseeable future. International collaboration will become an even more important element of the magnetic fusion energy program and will be incorporated into the inertial fusion energy program to the fullest practical extent. (National Energy Strategy, Executive Summary, 1991/1992) Research into fundamentally new, advanced energy sources such as [...] fusion energy can have substantial future payoffs... [T]he Nation's fusion program has made steady progress and last year set a record of producing 10.7 megawatts of power output at a test reactor supported by the Department of Energy. This development has significantly enhanced the prospects for demonstrating the scientific feasibility of fusion power, moving us one step closer to making this energy source available sometime in the next century. (Sustainable Energy Strategy, 1995) 258 CHAPTER 14 Nuclear fusion is essentially the antithesis of the fission process. Light nuclei are combined in order to release excess binding energy and they form a heavier nucleus. Fusion reactions are responsible for the energy of the sun. They have also been used on earth for uncontrolled release of large quantities of energy in the thermonuclear or ‘hydrogen’ bombs. However, at the present time, peaceful commercial applications of fusion reactions do not exist. The enormous potential and the problems associated with controlled use of this essentially nondepletable energy source are discussed briefly in this chapter.
    [Show full text]
  • 16. Fission and Fusion Particle and Nuclear Physics
    16. Fission and Fusion Particle and Nuclear Physics Dr. Tina Potter Dr. Tina Potter 16. Fission and Fusion 1 In this section... Fission Reactors Fusion Nucleosynthesis Solar neutrinos Dr. Tina Potter 16. Fission and Fusion 2 Fission and Fusion Most stable form of matter at A~60 Fission occurs because the total Fusion occurs because the two Fission low A nuclei have too large a Coulomb repulsion energy of p's in a surface area for their volume. nucleus is reduced if the nucleus The surface area decreases Fusion splits into two smaller nuclei. when they amalgamate. The nuclear surface The Coulomb energy increases, energy increases but its influence in the process, is smaller. but its effect is smaller. Expect a large amount of energy released in the fission of a heavy nucleus into two medium-sized nuclei or in the fusion of two light nuclei into a single medium nucleus. a Z 2 (N − Z)2 SEMF B(A; Z) = a A − a A2=3 − c − a + δ(A) V S A1=3 A A Dr. Tina Potter 16. Fission and Fusion 3 Spontaneous Fission Expect spontaneous fission to occur if energy released E0 = B(A1; Z1) + B(A2; Z2) − B(A; Z) > 0 Assume nucleus divides as A , Z A1 Z1 A2 Z2 1 1 where = = y and = = 1 − y A, Z A Z A Z A2, Z2 2 2=3 2=3 2=3 Z 5=3 5=3 from SEMF E0 = aSA (1 − y − (1 − y) ) + aC (1 − y − (1 − y) ) A1=3 @E0 maximum energy released when @y = 0 @E 2 2 Z 2 5 5 0 = a A2=3(− y −1=3 + (1 − y)−1=3) + a (− y 2=3 + (1 − y)2=3) = 0 @y S 3 3 C A1=3 3 3 solution y = 1=2 ) Symmetric fission Z 2 2=3 max.
    [Show full text]
  • Unit 3: Nuclear Reactors/Energy Generation
    Unit 3: Nuclear Reactors/Energy Generation Time: Three hours Objectives A. Teacher: 1. To ensure students understand how nuclear energy is generated. 2. To help students learn how a nuclear power plant works. 3. To understand how the NRC regulates commercial nuclear energy. B. At the conclusion of this unit the student should be able to — 1. Describe the fission process. 2. Identify the various kinds of nuclear power plants. 3. Discuss the process of energy generation with nuclear power plants. Investigation and Building Background 1. Introduce term: Students have little knowledge of nuclear reactors and limited understanding of the terminology used in nuclear power plants. Definitions found in dictionaries tend to be vague regarding this specialized language. 2. Resources: 1. Nuclear Power for Energy Generation "Nuclear Reactor Concepts" Workshop Manual, U.S. NRC 2. The Fission Process and Heat Production "Nuclear Reactor Concepts" Workshop Manual, U.S. NRC 3. Boiling-Water Reactor Systems "Nuclear Reactor Concepts" Workshop Manual, U.S. NRC 4. Pressurized-Water Reactor Systems "Nuclear Reactor Concepts" Workshop Manual, U.S. NRC 3. Generalizing: The purpose of a nuclear power plant is to produce or release heat and boil water. It is designed to produce electricity. It should be noted that while there are significant differences, there are many similarities between nuclear power plants and other electrical generating facilities. Uranium is used for fuel in nuclear power plants to make electricity. a. Vocabulary: Nuclear Power Plants boiling water reactor (BWR) helium pressurized water reactor (PWR) uranium dioxide uranium-235 uranium-238 sodium Questions 1. Is there a nuclear power plant near where you live? What type is it? 2.
    [Show full text]
  • Nuclear Reaction Rates
    9 – Nuclear reaction rates introduc)on to Astrophysics, C. Bertulani, Texas A&M-Commerce 1 9.1 – Nuclear decays: Neutron decay By increasing the neutron number, the gain in binding energy of a nucleus due to the volume term is exceeded by the loss due to the growing asymmetry term. After that, no more neutrons can be bound, the neutron drip line is reached beyond which, neutron decay occurs: (Z, N) à (Z, N - 1) + n (9.1) Q-value: Qn = m(Z, N) - m(Z, N-1) - mn (9.2) Neutron Separation Energy Sn Sn(Z, N) = m(Z, N-1) + mn - m(Z, N) = -Qn for n-decay (9.3) Neutron drip line: Sn = 0 Beyond the drip line Sn < 0 neutron unbound Gamma-decay • When a reaction places a nucleus in an excited state, it drops to the lowest energy through gamma emission • Excited states and decays in nuclei are similar to atoms: (a) they conserve angular momentum and parity, (b) the photon has spin = 1 and parity = -1 • For orbital with angular momentum L, parity is given by P= (-1)L • To first order, the photon carries away the energy from an electric dipole transition in nuclei. But in nuclei it is easier to have higher order terms in than in atoms. introduc)on to Astrophysics, C. Bertulani, Texas A&M-Commerce 2 Proton decay Proton Separation Energy Sp: Sp(Z,N) = m(Z-1,N) + mp - m(Z,N) (9.4) Proton drip line: Sp = 0 beyond the drip line: Sp < 0 the nuclei are proton unbound α-decay α-decay is the emission of an a particle ( = 4He nucleus) The Q-value for a decay is given by Q "m(Z,A) m(Z 2,A 4) m $c2 α = # − − − − α % (9.5) Decay lifetimes Nuclear lifetimes for decay through all the modes described so far depend not only on the Q-values, but also on the conservation of other physical quantities, such as angular momentum.
    [Show full text]
  • Handbook for Calculations of Nuclear Reaction Data, RIPL-2 Reference Input Parameter Library-2
    IAEA-TECDOC-1506 Handbook for calculations of nuclear reaction data, RIPL-2 Reference Input Parameter Library-2 Final report of a coordinated research project August 2006 IAEA-TECDOC-1506 Handbook for calculations of nuclear reaction data, RIPL-2 Reference Input Parameter Library-2 Final report of a coordinated research project August 2006 The originating Section of this publication in the IAEA was: Nuclear Data Section International Atomic Energy Agency Wagramer Strasse 5 P.O. Box 100 A-1400 Vienna, Austria HANDBOOK FOR CALCULATIONS OF NUCLEAR REACTION DATA, RIPL-2 IAEA, VIENNA, 2006 IAEA-TECDOC-1506 ISBN 92–0–105206–5 ISSN 1011–4289 © IAEA, 2006 Printed by the IAEA in Austria August 2006 FOREWORD Nuclear data for applications constitute an integral part of the IAEA programme of ac- tivities. When considering low-energy nuclear reactions induced with light particles, such as neutrons, protons, deuterons, alphas and photons, a broad range of applications are addressed, from nuclear power reactors and shielding design through cyclotron production of medical radioisotopes and radiotherapy to transmutation of nuclear waste. All these and many other applications require a detailed knowledge of production cross sections, spectra of emitted particles and their angular distributions. A long-standing problem of how to meet the nuclear data needs of the future with limited experimental resources puts a considerable demand upon nuclear model compu- tation capabilities. Originally, almost all nuclear data were provided by measurement programmes. Over time, theoretical understanding of nuclear phenomena has reached a high degree of reliability, and nuclear modeling has become standard practice in nuclear data evaluations (with measurements remaining critical for data testing and benchmark- ing).
    [Show full text]
  • Fact Sheet: What Is the Uranium Fuel Cycle? (PDF)
    What is the Uranium Fuel Cycle? Ofce of Radiation and Indoor Air (6608J) EPA 402-F-12-003 | September 2013 Milling of Reprocessing Uranium Ore Reprocessing is the initial Uranium is extracted separation of spent nuclear fuel Repository from ore with strong into its constituent parts. acids or bases. The Reprocessing is currently not uranium is concentrated taking place in the U.S. in a solid substance called “yellowcake.” Chemical Conversion Plants convert the uranium in yellowcake Spent Nuclear Fuel to uranium hexafuoride Used or “spent” nuclear (UF6), a compound fuel is stored in pools, or that can be made into in specially designed dry nuclear fuel. storage casks. Generation of Electricity at Nuclear Enrichment Power Plants Processing facilities Electricity is generated by concentrate uranium235-- nuclear power plants with the form (isotope) that is reactors that use water for capable of undergoing a moderating nuclear reactions nuclear reaction. and cooling. Fabrication of Fuel The enriched uranium is converted Dotted lines show EPAs’ “Environmental Radiation Protection Standards for processes that are into fuel pellets and placed into rods for use in nuclear power plants. Nuclear Power Operations” limit the radiation releases not currently taking and doses to the public from the normal operation of place in the U.S. uranium fuel facilities, including nuclear power plants. What is the Uranium Fuel Cycle? Environmental Radiation Protection Standards for Nuclear Power Operations Federal Register Reference—42 FR The Uranium Fuel Cycle: EPA and Nuclear 2860, Vol. 42, No. 9, January 13, 1977 Environmental Power Operations For more information, visit our website at: www.epa.gov/radiation/laws/190 Considerations EPA’s mission is to protect human health and the environment.
    [Show full text]
  • Nuclear Physics Sections 10.1-10.7
    James T. Shipman Jerry D. Wilson Charles A. Higgins, Jr. Chapter 10 Nuclear Physics Nuclear Physics • The characteristics of the atomic nucleus are important to our modern society. • Diagnosis and treatment of cancer and other diseases • Geological and archeological dating • Chemical analysis • Nuclear energy and nuclear diposal • Formation of new elements • Radiation of solar energy • Generation of electricity Audio Link Intro Early Thoughts about Elements • The Greek philosophers (600 – 200 B.C.) were the first people to speculate about the basic substances of matter. • Aristotle speculated that all matter on earth is composed of only four elements: earth, air, fire, and water. • He was wrong on all counts! Section 10.1 Names and Symbols of Common Elements Section 10.1 The Atom • All matter is composed of atoms. • An atom is composed of three subatomic particles: electrons (-), protons (+), and neutrons (0) • The nucleus of the atom contains the protons and the neutrons (also called nucleons.) • The electrons surround (orbit) the nucleus. • Electrons and protons have equal but opposite charges. Section 10.2 Major Constituents of an Atom Section 10.2 The Atomic Nucleus • Protons and neutrons have nearly the same mass and are 2000 times more massive than an electron. • Discovery – Electron (J.J. Thomson in 1897), Proton (Ernest Rutherford in 1918), and Neutron (James Chadwick in 1932) Section 10.2 Rutherford’s Alpha- Scattering Experiment • J.J. Thomson’s “plum pudding” model predicted the alpha particles would pass through the evenly distributed positive charges in the gold atoms. α particle = helium nucleus Section 10.2 Rutherford’s Alpha- Scattering Experiment • Only 1 out of 20,000 alpha particles bounced back.
    [Show full text]