NAME: DUE DATE: JULY nd AP Chemistry SUMMER REV: Balancing Nuclear Reactions Why? Nuclear reactions are going on all around us in the form of transmutation, fission and fusion. Using correctly balanced equations is important in order to determine the products as well as the energy emitted by these reactions. All equations need to be balanced to conform to two conservation laws: the mass number is conserved, and the electrical charge of the nucleus is conserved. (Note: These are all reactions involving the nucleus only, not the electrons in the energy levels surrounding the nucleus.) Success Criteria Use the conservation laws to find an unknown in a nuclear reaction equation. Write a balanced nuclear equation for a transmutation, fission, or fusion reaction. Information Nuclide = is an atomic species characterized by the specific constitution of its nucleus (protons and neutrons) Subatomic Particles: Proton = p Neutron = n Electron = e Alpha (α) Particle: 4 He = a helium nucleus Beta (β) Particles: e = beta/beta negative, electron e = beta positive, positron (antimatter) Model Subatomic Particles PARTICLE SYMBOL RELATIVE CHARGE RELATIVE MASS Proton Neutron Electron p + n e - /84. Label the mass number and atomic number (nuclear charge) for the generic symbol below.. Looking at the table, explain why a proton is symbolized as p. 3. Looking at the table, explain why a neutron is symbolized as n. 4. Looking at the table, explain why an electron is symbolized as e.
Model Particle Emission S U M M E R R E V : B a l a n c i n g N u c l e a r R e a c t i o n s 4 87Fr He 7 N e 6 5. Looking at the mass numbers and atomic numbers, how does the nucleus of the francium- atom change? What happens to the numbers of protons and neutrons? C e B 6 85 6 8 6 5 O At 6. Looking at the mass numbers and atomic numbers, how does the nucleus of the nitrogen-6 atom change? What happens to the numbers of protons and neutrons? 7. Looking at the mass numbers and atomic numbers, how does the nucleus of the carbon- atom change? What happens to the numbers of protons and neutrons? 8. a) What is the mass number of an alpha particle? b) What is the charge of an alpha particle? 9. a) What is the mass number of a beta particle? b) What are the possible charges of a beta particle? c) Why can a positron also be referred to as an anti-electron?. By examining the equations in Model, what is the mathematical relationship between the total mass number of the reactants and the total mass number of the products?. By examining the equations in the Model, what is the mathematical relationship between the total charge in the nuclei of the reactants and the total charge of the nuclei in the products?. How do your answers to and support the laws of conservation of mass number and nuclear charge?
Model 3 Nuclear Bombardment S U M M E R R E V : B a l a n c i n g N u c l e a r R e a c t i o n s 3 6 3 Al e 53I e 3 3. How do the reactions support the laws of conservation of mass number and nuclear charge? Show your work. 6 3 54 Mg Xe 4. In the change from aluminum-6 to magnesium-6, what particles are gained and lost in the nucleus? (Hint: Look at the Mass # and Atomic #.) 5. In the change from iodine-3 to xenon-3, what particles are gained and lost in the nucleus? Exercises 6. Use the laws of conservations of mass number and nuclear charge to determine the identity of the in the equations below. Refer to the periodic table as needed. 4 86Rn He 4 6C e e 9 9F 4 4 He 86Rn He e 7. Write balanced equations that describe the following nuclear decay reactions. A. Bismuth-4 undergoes beta decay. B. Neptunium - 37 undergoes alpha-decay. C. Nitrogen - 3 emits a positron. D. An alpha-decay reaction results in the formation of lead-6. MODEL 4 Fission versus Fusion
S U M M E R R E V : B a l a n c i n g N u c l e a r R e a c t i o n s 4 FISSION 35 9 36 4 U + n U (unstable) Ba + 9 Kr + 3 n 9 FUSION 56 36 3 H + H 4 He + n 8. What is used to trigger the fission reaction? How does it trigger the reaction? 9. How does the size of the reacting nucleus compare to the sizes of the product nuclei in a fission reaction?. How does the size of the reacting nucleus compare to the sizes of the product nuclei in a fusion reaction?. How do both types of reactions demonstrate the conservation of mass number and nuclear charge?. Identify the following equations as fission or fusion. Explain your choice.
A. H + H H + e + S U M M E R R E V : B a l a n c i n g N u c l e a r R e a c t i o n s 5 35 9 37 5 4 97 B. U + n Te + Zr + n 38 46 C. U + C Cf + 4 n 9 6 98 3 9 4 56 88 35 D. Pa + n Ba + Br + n 4 E. 4 H He + e + 37 93 4 53 35 9 F. Np + n I + Br + 3 n Exercises. Write equations for each of the following processes: 73 A. 3Ga produces a β particle. 68 B. 3Ga undergoes electron capture. 9 C. 78Pt produces an α particle. 35. What must be the end product of the natural radioactive series that begins with 9U and involves 7 alpha and 4 beta emissions? 3. Fill in the missing particle in each of the following equations:
S U M M E R R E V : B a l a n c i n g N u c l e a r R e a c t i o n s 6 9 A. 5Sb + e 6 4 + He B. Th 9 86 C. 77Ir + e D. + e 86Rn 4. Fill in the proper mass and charge numbers in the nuclear equations: 38 9U + n + e + e 5. The radioactive isotope 4 Cm undergoes decay to 6 Pb in the following order: α, α, α, α, α, α, α, β, β, α, β, β, α. Write the equations for each step.