Lec 1,2 Introduction to Nuclear Chemistry 2024 PDF

NUCLEAR CHEMISTRY BY Prof. Yusuf S. Alnajjar 1 10/30/2024  INTRODUCTION Why study nuclear chemistry 1. The stars and the sun are nuclear reactions. 2. Radioactive isotopes are used in many medical pr...

NUCLEAR CHEMISTRY BY Prof. Yusuf S. Alnajjar 1 10/30/2024  INTRODUCTION Why study nuclear chemistry 1. The stars and the sun are nuclear reactions. 2. Radioactive isotopes are used in many medical procedures. 3. Nuclear Power may be necessary for future energy needs. 2 10/30/2024  3 Contents 10/30/2024 1. Radioactivity in Nature 11. Nuclear Energy, Nuclear Reactors, Nuclear Fuel and Fuel Cycles 2. Radioelements, Isotopes and Radionuclides 12. Production of Radionuclides and Labelled 3. Physical Properties of Atomic Nuclei and Elementary Compounds Particles 13. Special Aspects of the Chemistry of Radionuclides 4. Radioactive Decay 14. Radioelements 5. Decay Modes 15. Dating by Nuclear Methods 6. Nuclear Radiation 16. Radio-analysis 7. Measurement of Nuclear Radiation 17. Radiotracers in Chemistry 8. Nuclear Reactions 18. Radionuclides in The Life Sciences 19. Radionuclides in the Geosphere and the Biosphere 9. Chemical Effects of Nuclear Reactions 20. Dosimetry and Radiation Protection 10. Influence of Chemical Bonding on Nuclear Properties  NUCLEAR CHEMISTRY In 1896, Henri Becquerel expanded the field of chemistry to include nuclear changes when he discovered that uranium emitted radiation. Marie Curie began studying radioactivity and completed much of the pioneering work on nuclear changes. Curie found that radiation was proportional to the amount of radioactive elements present Traditional chemistry reactions occur as a result of the interaction between valence electrons around an atom's nucleus. Nuclear chemistry is the chemistry that deals with the study of the atomic nucleus and nuclear changes. 4 10/30/2024  Chemical Reaction Nuclear reaction 1. Outside of nucleus 1. Inside of nucleus 2. Interaction between valence electrons 2. Interaction between components of the nucleus 3. Bond form and bond break. 3. Change in nucleus composition. 4. Associate with small energy changes. 4. Associated with large energy changes. 5. Atoms keep the same identity although they gain, lose 5. Atoms of one element are often converted into or share electrons and form new matter. another element. 6. T, P, conc. And catalysts affect reaction rates. 6. T, P, conc. And catalysts don’t normally affect reaction rates. 5 10/30/2024  𝑨 THE ATOMIC NUCLEUS 𝒁𝑿 A, is the mass number, and Z, is the atomic number. The protons and neutrons that make up the nucleus of an atom are called nucleons, and an atom with a particular number of protons and neutrons is called a nuclide. Nuclides with the same number of protons but different numbers of neutrons are called isotopes. 6 10/30/2024  NUCLEAR CHEMISTRY Any nucleus that is unstable and decays spontaneously is said to be radioactive, emitting subatomic particles and electromagnetic radiation. The emissions are collectively called radioactivity and can be measured. Isotopes that emit radiation are called radioisotopes. the rate at which radioactive decay occurs is characteristic of the isotope and is generally reported as a half-life (t1/2), the amount of time required for half of the initial number of nuclei present to decay in a first-order reaction. 7 10/30/2024  NUCLEAR STABILITY Electrostatic repulsions between positively charged protons would normally cause the nuclei of atoms (except H) to fly apart. In stable atomic nuclei, these repulsions are overcome by the strong nuclear force, a short-range but powerful attractive interaction between nucleons. If the attractive interactions due to the strong nuclear force are weaker than the electrostatic repulsions between protons, the nucleus is unstable, and it will eventually decay. 8 10/30/2024  COMPONENTS OF NUCLEUS Particle Symbol Charge (related to e-1) Mass (related to e) Electron(or negatron) e, β (e-, β-) -1 1 Positron e+, β+ +1 1 Proton p +1 1836.1 Neutron n 0 1838.6 9 10/30/2024  NUCLEAR BINDING ENERGIES Nuclear binding energy is the energy required to break up the nucleus into its separate nucleons or this can be expressed as the energy released when the nucleus is formed from separate nucleons. 10 10/30/2024  THE MASS DEFECT The mass defect is the mass difference between a nucleus and its constituent nucleons. The mass difference is changed to the binding energy of the nucleus. 11 10/30/2024  NUCLEAR BINDING ENERGIES EB (joule) = Δ m (kg) C2 (m/s) Δ m is the difference between the mass of the nucleus and the total mass of nucleons, C is the velocity of light, C = 3 x 108 m/s 12 10/30/2024  NUCLEAR BINDING ENERGIES EB (joule) = Δ mamu (1.6605x10-27) x (3 x 108)2 = (Δ mamu) 1.49445x10-10 j ∆𝑚𝑎𝑚𝑢 x1.49𝑥10−10 𝑗 EB (eV) = = ∆𝑚𝑎𝑚𝑢 𝑥 9.31𝑥108 eV 1.6𝑥10−19 ∆𝑚𝑎𝑚𝑢 𝑥 9.31𝑥108 eV EB (MeV) = = (Δ mamu ) x 931.5 MeV 𝟏𝟎𝟔 13 10/30/2024  EXAMPLE 1 Calculate the nuclear binding energy for the helium nucleus where the nucleus has a mass of 4.00150 amu. The mass of a proton is 1.00728 amu, and that of a neutron is 1.00866 amu. 14 10/30/2024  EXAMPLE 1 mass defect: binding energy Calculate the nuclear binding energy for the Δ m =( Zm + A m ) – m p n nucleus E=Δmc 2 helium nucleus where =(2(1.00728)+2(1.00866))-4.00150 the nucleus has -29 E= 5.04x10 x (3x10 ) a mass 8 2 of=0.03038 4.00150u amu. The mass E= 4.54of x 10 a Joule proton is -12 -27 = 0.030380 x 1.6605x10 =5.04x10 Kg -29 -12 -19 1.00728 amu, and that of aE=neutron 4.54x10 /(1.6x10 ) is 1.00866 7 E= 2.835 x 10 eV= 28.35 MeV amu. 15 10/30/2024  TRAINING EXERCISE: 16 10/30/2024  TRAINING EXERCISE: 17 10/30/2024  Calculate the mass defect and binding energy of 10 10 the nuclide 5B where the mass 5𝐵 atom = 10.0129 u. 18 10/30/2024  Oxygen has an unstable isotope O-17 that has a mass of 17.00454. If the mass of a neutron is 1.00898 u and the mass of a proton is 1.00814 u, calculate the binding energy of the oxygen nucleus in Mev. 19 10/30/2024  Calculate the mass defect of the following? 56 26Fe MFe= 55.934932 amu, 208 82Pb MPb= 207.976644 amu 235 92U MU= 235.043933 amu 20 10/30/2024  Write the nuclear symbol for each isotope using 𝑨𝒁𝑿 notation. 1. chlorine-39 2. lithium-8 3. osmium-183 4. zinc-71 5. lead-212 6. helium-5 7. oxygen-19 8. plutonium-242 21 10/30/2024  Give the number of protons, the number of neutrons, and the neutron-to-proton ratio for each isotope. 1. iron-57 2. W-185 3. potassium-39 4. Xe-131 5. technetium-99m 6. 140La 7. radium-227 8. 208Bi 22 10/30/2024 23 10/30/2024