1. Rutherford's alpha scattering experiment demonstrated that the positive charge and most of the mass of an atom is concentrated in a small, dense nucleus at the center.
2. The binding energy curve shows that binding energy per nucleon increases rapidly at first, peaks at iron-56, then gradually decreases, indicating the relative stability of nuclei.
3. Radioactive decay follows predictable laws: the rate of decay is proportional to the amount of radioactive material and independent of conditions; it occurs randomly with individual atoms. The decay constant λ defines the rate of decay.
1. Rutherford's alpha scattering experiment demonstrated that the positive charge and most of the mass of an atom are concentrated in a small, dense nucleus at the center. 2. The binding energy curve shows that binding energy per nucleon increases initially with mass number, peaks at iron-56, then decreases, making very large and very small nuclei unstable. 3. Radioactive decay follows predictable exponential laws, with the decay constant λ representing the probability of decay per unit time and half-life the time for half the nuclei to decay.
1. Rutherford's alpha scattering experiment provided evidence for the nuclear model of the atom, showing that the mass and positive charge of an atom are concentrated in a small, dense nucleus. Alpha particles scattering at large angles indicated a small, dense region at the center of the atom.
2. The document discusses properties of atomic nuclei including composition, size, density, binding energy, nuclear forces, radioactive decay, and the binding energy curve. Nuclear size is typically on the order of femtometers, and density is around 2.3×1017 kg/m3. Binding energy explains nuclear stability and radioactive decay. Nuclear forces are explained by meson exchange theory.
3. Key features of the binding energy curve
1. Rutherford's alpha scattering experiment provided evidence for the nuclear model of the atom, showing that the mass and positive charge of an atom are concentrated in a small, dense nucleus.
2. The binding energy curve shows that binding energy per nucleon initially rises with atomic mass number before peaking at iron-56 and then decreasing, indicating relative nuclear stability.
3. Radioactive decay follows first-order kinetics and the rate of decay is characterized by the disintegration constant λ, with the half-life period giving the time for half the radioactive nuclei to decay.
8m_ATOMS__NUCLEI.pdf chapter best notes preparation30jayporwal
Rutherford's alpha scattering experiment showed that the atom consists of a small, dense nucleus surrounded by empty space. Most alpha particles passed through the gold foil, but a small percentage were deflected at large angles, indicating the positive charge and mass of the atom are concentrated in a tiny nucleus. The nucleus is composed of protons and neutrons, with the number of protons defining the atomic number. Nuclear forces hold the nucleus together despite the repulsive electromagnetic forces between protons. Nuclear fusion and fission can release or absorb large amounts of energy due to the strong binding energy within atomic nuclei.
The document discusses various topics related to atoms and nuclei:
1. It summarizes Rutherford's alpha scattering experiment and what it revealed about the nuclear structure of atoms.
2. It then defines key nuclear properties - atomic number, mass number, nuclear radius, density and binding energy.
3. The document also covers nuclear forces, radioactivity, and the concept of half-life decay, explaining radioactive disintegration constants and units of radioactivity.
This document provides an overview of nuclear chemistry and radioactivity. It defines nuclear chemistry as the study of reactions involving changes in atomic nuclei. It describes the basics of atomic structure and the components of the nucleus. It then covers various nuclear reactions like radioactive decay, and types of radiation emitted. Key concepts discussed include radioactive half-life, rate of decay, and factors affecting nuclear stability. Classification of nuclides and various nuclear reactions like alpha, beta, and gamma decays are also summarized.
The document provides information on nuclear chemistry and radioactivity. It defines nuclear chemistry as the study of reactions involving changes in atomic nuclei. It describes the basic structure of the atom and defines key terms like isotopes, nuclides, and nuclear reactions. The document also discusses the classification of nuclides based on stability and magic numbers, as well as the forces that bind nucleons together and concepts like binding energy, mass defect, and radioactive decay.
This document discusses radioactivity and properties of the nucleus. It begins by defining radioactivity as the spontaneous emission of alpha, beta, and gamma rays by heavy elements. It then covers structure and properties of the nucleus, nuclear forces, radioactive decay, and laws of radioactive decay. Key points include: the nucleus contains protons and neutrons; nuclear forces bind protons and neutrons together; radioactive decay occurs via alpha, beta, or gamma emission; and the rate of radioactive decay follows an exponential decay model defined by the half-life. Binding energy is released during nuclear decay and is related to nuclear stability.
1. Rutherford's alpha scattering experiment demonstrated that the positive charge and most of the mass of an atom are concentrated in a small, dense nucleus at the center. 2. The binding energy curve shows that binding energy per nucleon increases initially with mass number, peaks at iron-56, then decreases, making very large and very small nuclei unstable. 3. Radioactive decay follows predictable exponential laws, with the decay constant λ representing the probability of decay per unit time and half-life the time for half the nuclei to decay.
1. Rutherford's alpha scattering experiment provided evidence for the nuclear model of the atom, showing that the mass and positive charge of an atom are concentrated in a small, dense nucleus. Alpha particles scattering at large angles indicated a small, dense region at the center of the atom.
2. The document discusses properties of atomic nuclei including composition, size, density, binding energy, nuclear forces, radioactive decay, and the binding energy curve. Nuclear size is typically on the order of femtometers, and density is around 2.3×1017 kg/m3. Binding energy explains nuclear stability and radioactive decay. Nuclear forces are explained by meson exchange theory.
3. Key features of the binding energy curve
1. Rutherford's alpha scattering experiment provided evidence for the nuclear model of the atom, showing that the mass and positive charge of an atom are concentrated in a small, dense nucleus.
2. The binding energy curve shows that binding energy per nucleon initially rises with atomic mass number before peaking at iron-56 and then decreasing, indicating relative nuclear stability.
3. Radioactive decay follows first-order kinetics and the rate of decay is characterized by the disintegration constant λ, with the half-life period giving the time for half the radioactive nuclei to decay.
8m_ATOMS__NUCLEI.pdf chapter best notes preparation30jayporwal
Rutherford's alpha scattering experiment showed that the atom consists of a small, dense nucleus surrounded by empty space. Most alpha particles passed through the gold foil, but a small percentage were deflected at large angles, indicating the positive charge and mass of the atom are concentrated in a tiny nucleus. The nucleus is composed of protons and neutrons, with the number of protons defining the atomic number. Nuclear forces hold the nucleus together despite the repulsive electromagnetic forces between protons. Nuclear fusion and fission can release or absorb large amounts of energy due to the strong binding energy within atomic nuclei.
The document discusses various topics related to atoms and nuclei:
1. It summarizes Rutherford's alpha scattering experiment and what it revealed about the nuclear structure of atoms.
2. It then defines key nuclear properties - atomic number, mass number, nuclear radius, density and binding energy.
3. The document also covers nuclear forces, radioactivity, and the concept of half-life decay, explaining radioactive disintegration constants and units of radioactivity.
This document provides an overview of nuclear chemistry and radioactivity. It defines nuclear chemistry as the study of reactions involving changes in atomic nuclei. It describes the basics of atomic structure and the components of the nucleus. It then covers various nuclear reactions like radioactive decay, and types of radiation emitted. Key concepts discussed include radioactive half-life, rate of decay, and factors affecting nuclear stability. Classification of nuclides and various nuclear reactions like alpha, beta, and gamma decays are also summarized.
The document provides information on nuclear chemistry and radioactivity. It defines nuclear chemistry as the study of reactions involving changes in atomic nuclei. It describes the basic structure of the atom and defines key terms like isotopes, nuclides, and nuclear reactions. The document also discusses the classification of nuclides based on stability and magic numbers, as well as the forces that bind nucleons together and concepts like binding energy, mass defect, and radioactive decay.
This document discusses radioactivity and properties of the nucleus. It begins by defining radioactivity as the spontaneous emission of alpha, beta, and gamma rays by heavy elements. It then covers structure and properties of the nucleus, nuclear forces, radioactive decay, and laws of radioactive decay. Key points include: the nucleus contains protons and neutrons; nuclear forces bind protons and neutrons together; radioactive decay occurs via alpha, beta, or gamma emission; and the rate of radioactive decay follows an exponential decay model defined by the half-life. Binding energy is released during nuclear decay and is related to nuclear stability.
Norman John Brodeur worked at MIT’s instrumentation lab which later became Draper Labs. My responsibility was instrumentation and guidance systems for the Apollo command module and the lunar module. Previous to that I worked for Avco-Everett Research Lab in Everett. There we focused on testing materials for the vehicle’s heat shield. I was doing heat studies of various materials and what we eventually developed would just burn off and the heat with it.
This document discusses the discovery of the neutron and basic nuclear properties such as size, shape, forces, and stability. Some key points:
- In 1932, Chadwick proposed neutrons to explain penetrating radiation produced from alpha particle bombardment of beryllium. This solved issues with electrons being in the nucleus.
- Nuclear sizes are on the order of femtometers and nuclear density is around 2.3×1017 kg/m3. Nuclear forces are strong but short-ranged, with a hard core repulsion at small distances.
- Deuteron binding energy was determined to be 2.22 MeV from photodisintegration experiments. Its spin and magnetic moment provided evidence that the neutron and proton
Med.physics dr. ismail atomic and nuclear physics Ismail Syed
This document discusses various topics in nuclear and atomic physics including:
- Photon and electromagnetic radiation being quantized into particles called photons according to Einstein's theory.
- Photoelectric effect where photons eject electrons from metal surfaces.
- De Broglie hypothesis of matter waves associated with moving particles.
- Rutherford's model of the atom consisting of a small, dense nucleus surrounded by electrons.
- Isotopes being nuclei with the same number of protons but different numbers of neutrons.
- Nuclear radius increasing with the cube root of the atomic mass number based on measurements.
- Radioactive decay, half life, activity, and the relationship between decay constant and half life.
Nuclear physics covers many topics including the discovery of the nucleus, nuclear properties, nuclear binding energies, radioactivity, and nuclear models. Rutherford's gold foil experiment in 1911 provided evidence for the small, dense nucleus by detecting alpha particles scattered at large angles. The nucleus was found to be about 100,000 times smaller than the atom but containing almost all of its mass. Nuclear binding energy refers to the energy required to separate a nucleus into its constituent protons and neutrons and provides a measure of nuclear stability, with the most tightly bound nuclei having the greatest binding energy per nucleon.
1. Nuclear physics studies the composition and interactions of atomic nuclei. Nuclei are composed of protons and neutrons, which interact via the strong nuclear force.
2. Nuclear reactions such as fission, fusion, and radioactive decay involve changes in nuclear binding energies and mass defects. Fission releases energy as heavy nuclei split into lighter nuclei, while fusion releases energy by combining light nuclei into heavier ones.
3. Key concepts include the strong nuclear force, mass defect and binding energy, radioactive decay and half-lives, and the types of radiation involved in different nuclear reactions like fission and fusion.
STRUCTURE OF ATOM
Sub atomic Particles
Atomic Models
Atomic spectrum of hydrogen atom:
Photoelectric effect
Planck’s quantum theory
Heisenberg’s uncertainty principle
Quantum Numbers
Rules for filling of electrons in various orbitals
This document provides an introduction to nuclear chemistry. It discusses the basic components of atoms and how nuclear reactions differ from chemical reactions. It describes the three types of nuclear radiation (alpha, beta, gamma) and their properties. The document also covers radioactive decay and concepts such as decay constant, half-life, and average life. Additional topics include nuclear stability factors, mass defect and binding energy, and the application of radioisotopes as tracers and in radiotherapy, mutation breeding, and carbon dating.
1) In 1932, Chadwick proposed that the new radiation produced by alpha particles striking beryllium consisted of neutral particles called neutrons, estimating their mass to be close to the modern value of 1.0087 atomic mass units.
2) Neutrons have no electric charge, allowing them to penetrate matter more easily than charged particles and induce nuclear reactions. Their magnetic moments are on the same order of magnitude as protons, indicating they are not composed of electrons.
3) The deuteron, consisting of one proton and one neutron, has a binding energy of 2.22 MeV as determined through photodisintegration experiments. Its nuclear magnetic moment is slightly less than the sum of the proton and neutron magnetic moments
The document discusses subatomic physics and the fundamental interactions and particles that govern it. It introduces the four fundamental interactions - gravity, electromagnetism, strong, and weak. It describes the standard model of particle physics, which includes 12 matter particles (6 quarks and 6 leptons) and 12 force-carrying particles. It discusses how mass and energy are equivalent according to Einstein's famous equation E=mc2. The strong nuclear force binds protons and neutrons together in the tiny nucleus at the center of atoms.
This document discusses atomic structure and periodicity. It begins by explaining electromagnetic radiation and its wave characteristics. It then discusses Planck's discovery that energy is quantized and Einstein's proposal that light can be viewed as particles called photons. Next, it explains the photoelectric effect and how it provided evidence that light behaves as particles. It discusses the Bohr model of the hydrogen atom and how it correctly predicted the atom's quantized energy levels but was fundamentally incorrect. Finally, it summarizes the development of the modern quantum mechanical model of the atom and periodic trends in atomic properties such as ionization energy and atomic radius.
Nuclear physics describes the structure and interactions of atomic nuclei. Rutherford discovered the nucleus through alpha scattering experiments. Protons and neutrons were later identified. Isotopes have the same number of protons but different numbers of neutrons. Mass defect and binding energy explain why atomic nuclei are more stable than separated nucleons. Radioactive decay occurs spontaneously at a rate proportional to the number of unstable nuclei. Exponential decay and half-life are described by the decay constant. Nuclear reactions conserve nucleon number and charge. Energy is released or absorbed through mass-energy equivalence. Fission and fusion occur under different conditions according to binding energy. Controlled fission in reactors uses moderation and feedback to sustain a chain reaction. Fusion
This document summarizes key concepts in atomic structure:
1. It outlines the early theories of Dalton, Thomson, Rutherford, and Bohr, which proposed that atoms are made of fundamental particles and have small, dense nuclei surrounded by orbiting electrons.
2. It describes experiments that discovered the electron and properties of cathode rays. Rutherford's gold foil experiment provided evidence for a small, dense nucleus.
3. Quantum theory concepts like Planck's quantum hypothesis, Bohr's model of electron orbits, and de Broglie's matter waves are introduced along with equations relating wavelength, frequency and energy of photons.
This document discusses the discovery of artificial radioactivity by Curie and Joliot in 1934. When boron and aluminum were bombarded with alpha particles, the target nuclei continued emitting radiation even after the alpha source was removed. Through experiments, they determined the radiation consisted of positrons, positively charged particles with mass equal to electrons. Curie and Joliot explained that bombarding the elements created unstable nuclei that spontaneously disintegrated. For boron, this produced radioactive nitrogen that decayed to stable carbon with a half-life of 10.1 minutes by emitting a positron. For aluminum, it produced radioactive phosphorus with a half-life of about 3 minutes that decayed to stable phosphorus. This demonstrated the
1. Nuclear chemistry deals with changes in the nucleus of atoms, which are the source of radioactivity and nuclear power. It studies nuclear particles, forces, and reactions.
2. Nuclear reactions differ from chemical reactions in that the nucleus of an element takes part rather than just electrons, and a much larger amount of energy is evolved. Reaction rates of nuclear reactions are dependent on nuclear concentration but not influenced by temperature or catalysts.
3. Radioactive decay occurs via three types of radiation: alpha, beta, and gamma. Alpha decay decreases mass and atomic number by units of 4 and 2, respectively. Beta decay does not change mass number but increases atomic number by 1. Gamma decay does not change mass or atomic number
The document discusses nuclear models, specifically the liquid drop model. It provides three key points:
1. The liquid drop model views the nucleus as similar to a liquid drop, with nucleons interacting through short-range forces like molecules in a liquid. This explains trends in binding energy with mass number.
2. The Beithe-Weizsacker formula provides a semi-empirical expression for binding energy as a function of mass and atomic number. It includes terms for volume, surface tension, electrostatic repulsion and asymmetry.
3. The formula allows predicting stability against alpha or beta decay. Alpha decay energy can be calculated and nuclei with mass over 200 are predicted to alpha decay. Mass parabol
1. The document covers topics in nuclear physics including nuclear structure, radioactive decay, nuclear reactions like fission and fusion, and elementary particles.
2. Nuclear structure explains that the nucleus is made up of protons and neutrons and is surrounded by electrons. Nuclear stability depends on the balance of protons and neutrons.
3. Radioactive decay occurs when an unstable nucleus spontaneously emits radiation to become more stable. Different types of decay emit alpha, beta, or gamma radiation. Half-life is used to calculate decay rates over time.
Rutherford's model of the atom proposed that:
1. Most alpha particles passed through the atom undeflected, indicating most of the atom is empty space.
2. Some alpha particles were deflected, indicating a small, positively charged nucleus at the center of the atom.
3. Very few alpha particles were reflected backwards, showing the nucleus occupies an extremely small volume compared to the atom.
This model explained experimental observations of alpha particle scattering and established the basics of atomic structure, including the small, dense nucleus at the center of the atom.
1. Lord Rutherford discovered the nucleus through alpha particle scattering experiments, finding that atoms consist of a small, dense, positively charged nucleus surrounded by orbiting electrons.
2. The nucleus contains positively charged protons and neutral neutrons, collectively called nucleons. The number of protons is the atomic number and the total number of protons and neutrons is the mass number.
3. Isotopes are atoms with the same atomic number but different mass numbers, such as the three isotopes of hydrogen: deuterium, ordinary hydrogen, and tritium.
The document summarizes the history and key discoveries related to radioactivity and nuclear physics. It discusses how Becquerel discovered radioactivity in uranium in 1896, leading the Curies to isolate the elements polonium and radium. It then covers atomic structure, the different types of radioactive decay, units of radioactivity, decay processes, and nuclear reactions including fission and fusion.
This document discusses the development of atomic structure models from the early 20th century to the present. It describes experiments that showed light and matter have both wave-like and particle-like properties. This led to the development of quantum mechanics and quantum numbers to describe electron orbitals. The Bohr model of the hydrogen atom was an early success but did not apply to other atoms. Modern quantum mechanics uses probability distributions and accounts for electron spin and the Pauli exclusion principle.
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
Norman John Brodeur worked at MIT’s instrumentation lab which later became Draper Labs. My responsibility was instrumentation and guidance systems for the Apollo command module and the lunar module. Previous to that I worked for Avco-Everett Research Lab in Everett. There we focused on testing materials for the vehicle’s heat shield. I was doing heat studies of various materials and what we eventually developed would just burn off and the heat with it.
This document discusses the discovery of the neutron and basic nuclear properties such as size, shape, forces, and stability. Some key points:
- In 1932, Chadwick proposed neutrons to explain penetrating radiation produced from alpha particle bombardment of beryllium. This solved issues with electrons being in the nucleus.
- Nuclear sizes are on the order of femtometers and nuclear density is around 2.3×1017 kg/m3. Nuclear forces are strong but short-ranged, with a hard core repulsion at small distances.
- Deuteron binding energy was determined to be 2.22 MeV from photodisintegration experiments. Its spin and magnetic moment provided evidence that the neutron and proton
Med.physics dr. ismail atomic and nuclear physics Ismail Syed
This document discusses various topics in nuclear and atomic physics including:
- Photon and electromagnetic radiation being quantized into particles called photons according to Einstein's theory.
- Photoelectric effect where photons eject electrons from metal surfaces.
- De Broglie hypothesis of matter waves associated with moving particles.
- Rutherford's model of the atom consisting of a small, dense nucleus surrounded by electrons.
- Isotopes being nuclei with the same number of protons but different numbers of neutrons.
- Nuclear radius increasing with the cube root of the atomic mass number based on measurements.
- Radioactive decay, half life, activity, and the relationship between decay constant and half life.
Nuclear physics covers many topics including the discovery of the nucleus, nuclear properties, nuclear binding energies, radioactivity, and nuclear models. Rutherford's gold foil experiment in 1911 provided evidence for the small, dense nucleus by detecting alpha particles scattered at large angles. The nucleus was found to be about 100,000 times smaller than the atom but containing almost all of its mass. Nuclear binding energy refers to the energy required to separate a nucleus into its constituent protons and neutrons and provides a measure of nuclear stability, with the most tightly bound nuclei having the greatest binding energy per nucleon.
1. Nuclear physics studies the composition and interactions of atomic nuclei. Nuclei are composed of protons and neutrons, which interact via the strong nuclear force.
2. Nuclear reactions such as fission, fusion, and radioactive decay involve changes in nuclear binding energies and mass defects. Fission releases energy as heavy nuclei split into lighter nuclei, while fusion releases energy by combining light nuclei into heavier ones.
3. Key concepts include the strong nuclear force, mass defect and binding energy, radioactive decay and half-lives, and the types of radiation involved in different nuclear reactions like fission and fusion.
STRUCTURE OF ATOM
Sub atomic Particles
Atomic Models
Atomic spectrum of hydrogen atom:
Photoelectric effect
Planck’s quantum theory
Heisenberg’s uncertainty principle
Quantum Numbers
Rules for filling of electrons in various orbitals
This document provides an introduction to nuclear chemistry. It discusses the basic components of atoms and how nuclear reactions differ from chemical reactions. It describes the three types of nuclear radiation (alpha, beta, gamma) and their properties. The document also covers radioactive decay and concepts such as decay constant, half-life, and average life. Additional topics include nuclear stability factors, mass defect and binding energy, and the application of radioisotopes as tracers and in radiotherapy, mutation breeding, and carbon dating.
1) In 1932, Chadwick proposed that the new radiation produced by alpha particles striking beryllium consisted of neutral particles called neutrons, estimating their mass to be close to the modern value of 1.0087 atomic mass units.
2) Neutrons have no electric charge, allowing them to penetrate matter more easily than charged particles and induce nuclear reactions. Their magnetic moments are on the same order of magnitude as protons, indicating they are not composed of electrons.
3) The deuteron, consisting of one proton and one neutron, has a binding energy of 2.22 MeV as determined through photodisintegration experiments. Its nuclear magnetic moment is slightly less than the sum of the proton and neutron magnetic moments
The document discusses subatomic physics and the fundamental interactions and particles that govern it. It introduces the four fundamental interactions - gravity, electromagnetism, strong, and weak. It describes the standard model of particle physics, which includes 12 matter particles (6 quarks and 6 leptons) and 12 force-carrying particles. It discusses how mass and energy are equivalent according to Einstein's famous equation E=mc2. The strong nuclear force binds protons and neutrons together in the tiny nucleus at the center of atoms.
This document discusses atomic structure and periodicity. It begins by explaining electromagnetic radiation and its wave characteristics. It then discusses Planck's discovery that energy is quantized and Einstein's proposal that light can be viewed as particles called photons. Next, it explains the photoelectric effect and how it provided evidence that light behaves as particles. It discusses the Bohr model of the hydrogen atom and how it correctly predicted the atom's quantized energy levels but was fundamentally incorrect. Finally, it summarizes the development of the modern quantum mechanical model of the atom and periodic trends in atomic properties such as ionization energy and atomic radius.
Nuclear physics describes the structure and interactions of atomic nuclei. Rutherford discovered the nucleus through alpha scattering experiments. Protons and neutrons were later identified. Isotopes have the same number of protons but different numbers of neutrons. Mass defect and binding energy explain why atomic nuclei are more stable than separated nucleons. Radioactive decay occurs spontaneously at a rate proportional to the number of unstable nuclei. Exponential decay and half-life are described by the decay constant. Nuclear reactions conserve nucleon number and charge. Energy is released or absorbed through mass-energy equivalence. Fission and fusion occur under different conditions according to binding energy. Controlled fission in reactors uses moderation and feedback to sustain a chain reaction. Fusion
This document summarizes key concepts in atomic structure:
1. It outlines the early theories of Dalton, Thomson, Rutherford, and Bohr, which proposed that atoms are made of fundamental particles and have small, dense nuclei surrounded by orbiting electrons.
2. It describes experiments that discovered the electron and properties of cathode rays. Rutherford's gold foil experiment provided evidence for a small, dense nucleus.
3. Quantum theory concepts like Planck's quantum hypothesis, Bohr's model of electron orbits, and de Broglie's matter waves are introduced along with equations relating wavelength, frequency and energy of photons.
This document discusses the discovery of artificial radioactivity by Curie and Joliot in 1934. When boron and aluminum were bombarded with alpha particles, the target nuclei continued emitting radiation even after the alpha source was removed. Through experiments, they determined the radiation consisted of positrons, positively charged particles with mass equal to electrons. Curie and Joliot explained that bombarding the elements created unstable nuclei that spontaneously disintegrated. For boron, this produced radioactive nitrogen that decayed to stable carbon with a half-life of 10.1 minutes by emitting a positron. For aluminum, it produced radioactive phosphorus with a half-life of about 3 minutes that decayed to stable phosphorus. This demonstrated the
1. Nuclear chemistry deals with changes in the nucleus of atoms, which are the source of radioactivity and nuclear power. It studies nuclear particles, forces, and reactions.
2. Nuclear reactions differ from chemical reactions in that the nucleus of an element takes part rather than just electrons, and a much larger amount of energy is evolved. Reaction rates of nuclear reactions are dependent on nuclear concentration but not influenced by temperature or catalysts.
3. Radioactive decay occurs via three types of radiation: alpha, beta, and gamma. Alpha decay decreases mass and atomic number by units of 4 and 2, respectively. Beta decay does not change mass number but increases atomic number by 1. Gamma decay does not change mass or atomic number
The document discusses nuclear models, specifically the liquid drop model. It provides three key points:
1. The liquid drop model views the nucleus as similar to a liquid drop, with nucleons interacting through short-range forces like molecules in a liquid. This explains trends in binding energy with mass number.
2. The Beithe-Weizsacker formula provides a semi-empirical expression for binding energy as a function of mass and atomic number. It includes terms for volume, surface tension, electrostatic repulsion and asymmetry.
3. The formula allows predicting stability against alpha or beta decay. Alpha decay energy can be calculated and nuclei with mass over 200 are predicted to alpha decay. Mass parabol
1. The document covers topics in nuclear physics including nuclear structure, radioactive decay, nuclear reactions like fission and fusion, and elementary particles.
2. Nuclear structure explains that the nucleus is made up of protons and neutrons and is surrounded by electrons. Nuclear stability depends on the balance of protons and neutrons.
3. Radioactive decay occurs when an unstable nucleus spontaneously emits radiation to become more stable. Different types of decay emit alpha, beta, or gamma radiation. Half-life is used to calculate decay rates over time.
Rutherford's model of the atom proposed that:
1. Most alpha particles passed through the atom undeflected, indicating most of the atom is empty space.
2. Some alpha particles were deflected, indicating a small, positively charged nucleus at the center of the atom.
3. Very few alpha particles were reflected backwards, showing the nucleus occupies an extremely small volume compared to the atom.
This model explained experimental observations of alpha particle scattering and established the basics of atomic structure, including the small, dense nucleus at the center of the atom.
1. Lord Rutherford discovered the nucleus through alpha particle scattering experiments, finding that atoms consist of a small, dense, positively charged nucleus surrounded by orbiting electrons.
2. The nucleus contains positively charged protons and neutral neutrons, collectively called nucleons. The number of protons is the atomic number and the total number of protons and neutrons is the mass number.
3. Isotopes are atoms with the same atomic number but different mass numbers, such as the three isotopes of hydrogen: deuterium, ordinary hydrogen, and tritium.
The document summarizes the history and key discoveries related to radioactivity and nuclear physics. It discusses how Becquerel discovered radioactivity in uranium in 1896, leading the Curies to isolate the elements polonium and radium. It then covers atomic structure, the different types of radioactive decay, units of radioactivity, decay processes, and nuclear reactions including fission and fusion.
This document discusses the development of atomic structure models from the early 20th century to the present. It describes experiments that showed light and matter have both wave-like and particle-like properties. This led to the development of quantum mechanics and quantum numbers to describe electron orbitals. The Bohr model of the hydrogen atom was an early success but did not apply to other atoms. Modern quantum mechanics uses probability distributions and accounts for electron spin and the Pauli exclusion principle.
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
Walmart Business+ and Spark Good for Nonprofits.pdfTechSoup
"Learn about all the ways Walmart supports nonprofit organizations.
You will hear from Liz Willett, the Head of Nonprofits, and hear about what Walmart is doing to help nonprofits, including Walmart Business and Spark Good. Walmart Business+ is a new offer for nonprofits that offers discounts and also streamlines nonprofits order and expense tracking, saving time and money.
The webinar may also give some examples on how nonprofits can best leverage Walmart Business+.
The event will cover the following::
Walmart Business + (https://business.walmart.com/plus) is a new shopping experience for nonprofits, schools, and local business customers that connects an exclusive online shopping experience to stores. Benefits include free delivery and shipping, a 'Spend Analytics” feature, special discounts, deals and tax-exempt shopping.
Special TechSoup offer for a free 180 days membership, and up to $150 in discounts on eligible orders.
Spark Good (walmart.com/sparkgood) is a charitable platform that enables nonprofits to receive donations directly from customers and associates.
Answers about how you can do more with Walmart!"
LAND USE LAND COVER AND NDVI OF MIRZAPUR DISTRICT, UPRAHUL
This Dissertation explores the particular circumstances of Mirzapur, a region located in the
core of India. Mirzapur, with its varied terrains and abundant biodiversity, offers an optimal
environment for investigating the changes in vegetation cover dynamics. Our study utilizes
advanced technologies such as GIS (Geographic Information Systems) and Remote sensing to
analyze the transformations that have taken place over the course of a decade.
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9
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What is Digital Literacy? A guest blog from Andy McLaughlin, University of Ab...
atomic_nucleus.ppt
1. ATOMIC NUCLEUS
1. Rutherford’s Alpha Scattering Experiment
2. Distance of Closest Approach (Nuclear Size)
3. Impact Parameter
4. Composition of Nucleus
5. Atomic Number, Mass Number and Atomic Mass Unit
6. Radius of the Nucleus and Nuclear Density
7. Mass Energy Relation and Mass Defect
8. Binding Energy and Binding Energy per Nucleon
9. Binding Energy Curve and Inferences
10.Nuclear Forces and Meson Theory
11.Radioactivity and Soddy’s Displacement Law
12.Rutherford and Soddy’s Laws of Radioactive Decay
13.Radioactive Disintegration Constant and Half-Life Period
14.Units of Radioactivity
15.Nuclear Fission and Fusion
Created by C. Mani, Principal, K V No.1, Jalahalli (W), Bangalore
2. Rutherford’s Alpha Scattering Experiment
+
Lead Box
Bi-214 or
Radon
α - Beam
Thin
Gold Foil
ZnS Screen
Gold Atom
α - Beam
Scattering angle (θ)
No.
of
α-particles
scattered
(N)
α
α
3. Alpha – particle is a nucleus of helium atom carrying a charge of ‘+2e’ and
mass equal to 4 times that of hydrogen atom. It travels with a speed nearly
104 m/s and is highly penetrating.
Rutherford
Experiment
Geiger &
Marsden
Experiment
Source of
α-particle
Radon
86Rn222
Bismuth
83Bi214
Speed of
α-particle
104 m/s 1.6 x 107 m/s
Thickness of
Gold foil
10-6 m 2.1 x 10-7 m
4. S. No. Observation Conclusion
1 Most of the α-particles passed
straight through the gold foil.
It indicates that most of the space
in an atom is empty.
2 Some of the α-particles were
scattered by only small angles,
of the order of a few degrees.
α-particles being +vely charged and
heavy compared to electron could
only be deflected by heavy and
positive region in an atom. It
indicates that the positive charges
and the most of the mass of the
atom are concentrated at the centre
called ‘nucleus’.
3 A few α-particles (1 in 9000)
were deflected through large
angles (even greater than 90°).
Some of them even retraced
their path. i.e. angle of
deflection was 180°.
α-particles which travel towards the
nucleus directly get retarded due to
Coulomb’s force of repulsion and
ultimately comes to rest and then
fly off in the opposite direction.
N(θ) α
1
sin4(θ/2)
5. Distance of Closest Approach (Nuclear size):
+
r0
When the distance between α-particle
and the nucleus is equal to the distance
of the closest approach (r0), the α-particle
comes to rest.
At this point or distance, the kinetic
energy of α-particle is completely
converted into electric potential energy
of the system.
½ mu2 =
1
4πε0
2 Ze2
r0
r0 =
1
4πε0
2 Ze2
½ mu2
6. Impact Parameter (b):
+
r0
The perpendicular distance of the
velocity vector of the α-particle from
the centre of the nucleus when it is
far away from the nucleus is known
as impact parameter.
θ
b
u
b =
4πε0
Ze2
(½ mu2)
cot (θ/2)
i) For large value of b, cot θ/2 is large and θ, the scattering angle is small.
i.e. α-particles travelling far away from the nucleus suffer small deflections.
ii) For small value of b, cot θ/2 is also small and θ, the scattering angle is large.
i.e. α-particles travelling close to the nucleus suffer large deflections.
iii) For b = 0 i.e. α-particles directed towards the centre of the nucleus,
cot θ/2 = 0 or θ/2 = 90° or θ = 180°
The α-particles retrace their path.
7. Composition of Nucleus:
Every atomic nucleus except that of Hydrogen has two types of particles –
protons and neutrons. (Nucleus of Hydrogen contains only one proton)
Proton is a fundamental particle with positive charge 1.6 x 10-19 C and
mass 1.67 x 10-27 kg (1836 times heavier than an electron).
Neutron is also a fundamental particle with no charge and
mass 1.675 x 10-27 kg (1840 times heavier than an electron).
Atomic Number (Z):
The number of protons in a nucleus of an atom is called atomic number.
Atomic Mass Number (A):
The sum of number of protons and number of neutrons in a nucleus of an
atom is called atomic mass number.
A = Z + N
Atomic Mass Unit (amu):
Atomic Mass Unit (amu) is (1 / 12)th of mass of 1 atom of carbon.
1 amu =
1
12
12
x
6.023 x 1023
g = 1.66 x 10-27 kg
8. Size of Nucleus:
Nucleus does not have a sharp or well-defined boundary.
However, the radius of nucleus can be given by
R = R0 A⅓ where R0 = 1.2 x 10-5 m is a constant which is the
same for all nuclei and
A is the mass number of the nucleus.
Radius of nucleus ranges from 1 fm to 10 fm.
Nuclear Volume, V = (4/3) π R3 = (4/3) π R0
3 A
V α A
Nucleus Density:
Mass of nucleus, M = A amu = A x 1.66 x 10-27 kg
Nuclear Volume, V = (4/3) π R3 = (4/3) π R0
3 A
4
3
22
7
x
= x (1.2 x 10-15)3 A m3
= 7.24 x 10-45 A m3
Nucleus Density, ρ = M / V = 2.29 x 1017 kg / m3
9. Discussion:
1. The nuclear density does not depend upon mass number. So, all
the nuclei possess nearly the same density.
2. The nuclear density has extremely large value. Such high
densities are found in white dwarf stars which contain mainly
nuclear matter.
3. The nuclear density is not uniform throughout the nucleus. It has
maximum value at the centre and decreases gradually as we move
away from the centre of the nucleus.
4. The nuclear radius is the distance from the centre of the nucleus
at which the density of nuclear matter decreases to one-half of its
maximum value at the centre.
10. Mass – Energy Relation:
According to Newton’s second law of motion, force acting on a body is
defined as the rate of change of momentum.
d
dt
F = (mv)
dv
dt
= m
dm
dt
+ v
If this force F displaces the body by a distance dx, its energy increases by
dv
dt
= m
dK = F.dx dx
dm
dt
+ v dx
dx
dt
= m
dK dv
dx
dt
+ v dm
= m v dv + v2 dm ………… (1)
dK
According to Einstein’s relation of relativistic mass,
m =
m0
[1 – (v2 / c2)]½
11. Squaring and manipulating, m2c2 – m2v2 = m0
2c2
Differentiating (with m0 and c as constants)
c2 2m dm – m2 2v dv – v2 2m dm = 0
c2 dm – mv dv – v2 dm = 0
c2 dm = mv dv + v2 dm ……………..(2)
From (1) and (2), dK = dm c2
If particle is accelerated from rest to a velocity v, let its mass m0 increases to m.
Integrating,
Total increase in K.E. =
0
K
dK = c2 dm
m0
m
K = (m – m0) c2 or K + m0 c2 = m c2
Here m0c2 is the energy associated with the rest mass of the body and K is the
kinetic energy.
Thus, the total energy of the body is given by
or
E = m c2
This is Einstein’s mass - energy equivalence relation.
12. Mass Defect:
It is the difference between the rest mass of the nucleus and the sum of the
masses of the nucleons composing a nucleus is known as mass defect.
Δm = [ Zmp + (A – Z) mn ] - M
Mass defect per nucleon is called packing fraction.
Binding Energy:
It is the energy required to break up a nucleus into its constituent parts and
place them at an infinite distance from one another.
B.E = Δm c2
Nuclear Forces:
They are the forces between p – p, p – n or n – n in the nucleus. They can be
explained by Meson Theory.
There are three kinds of mesons – positive (π+), negative (π-) and neutral (π0).
π+ and π- are 273 times heavier than an electron.
π0 is 264 times heavier than an electron.
Nucleons (protons and neutrons) are surrounded by mesons.
13. Main points of Meson Theory:
1. There is a continuous exchange of a meson between one nucleon and
other. This gives rise to an exchange force between them and keep
them bound.
2. Within the nucleus, a neutron is never permanently a neutron and a
proton is never permanently a proton. They keep on changing into each
other due to exchange of π-mesons.
3. The n – n forces arise due to exchange of π0 – mesons between the
neutrons.
n → n + π0 (emission of π0)
n + π0 → n (absorption of π0)
4. The p – p forces arise due to exchange of π0 – mesons between the
protons.
p → p + π0 (emission of π0)
p + π0 → p (absorption of π0)
14. 5. The n – p forces arise due to exchange of π+ and π- mesons between the
nucleons.
n → p + π- (emission of π-)
n + π+ → p (absorption of π+)
p → n + π+ (emission of π+)
p + π- → n (absorption of π-)
6. The time involved in such an exchange is so small that the free meson
particles cannot be detected as such.
Binding Energy per Nucleon:
It is the binding energy divided by total number of nucleons.
It is denoted by B
B = B.E / Nucleon = Δm c2 / A
15. 0 20 40 60 80 100 120 140 160 180 200 220 240
Mass Number (A)
Average
B.E
per
Nucleon
(in
MeV)
6
7
5
1
4
8
3
9
2
8.8
Region
of
maximum
stability
Fission
Fusion
Binding Energy Curve:
Special Features:
1. Binding energy per nucleon of very light
nuclides such as 1H2 is very small.
2. Initially, there is a rapid rise in the value
of binding energy per nucleon.
3. Between mass numbers 4 and 20, the
curve shows cyclic recurrence of peaks
corresponding to 2He4, 4Be8, 6C12, 8O16 and
10Ne20. This shows that the B.E. per
nucleon of these nuclides is greater than
those of their immediate neighbours.
4. After A = 20, there is a gradual increase in
B.E. per nucleon. The maximum value of 8.8
MeV is reached at A = 56. Therefore, Iron
nucleus is the most stable.
5. Binding energy per nucleon of nuclides
having mass numbers ranging from 40
to 120 are close to the maximum value.
So, these elements are highly stable and
non-radioactive.
6. Beyond A = 120, the value decreases
and falls to 7.6 MeV for Uranium.
7. Beyond A = 128, the value shows a rapid
decrease. This makes elements beyond
Uranium (trans – uranium elements)
quite unstable and radioactive.
8. The drooping of the curve at high mass
number indicates that the nucleons are
more tightly bound and they can
undergo fission to become stable.
9. The drooping of the curve at low mass
numbers indicates that the nucleons can
undergo fusion to become stable.
56
Li7
Li6
He4
Be11
C12
N14
F19
Be9
O16
Ne20
Al27 Cl35 Ar40
Fe56
Mo98
Xe124
Xe136
Xe130
As75
Sr86
Cu63
W182
Pt208
U235
U238
Pt194
H1
H2
H3
He3
16. 1. Binding energy per nucleon of very light nuclides such as 1H2 is very small.
2. Initially, there is a rapid rise in the value of binding energy per nucleon.
3. Between mass numbers 4 and 20, the curve shows cyclic recurrence of
peaks corresponding to 2He4, 4Be8, 6C12, 8O16 and 10Ne20. This shows that the
B.E. per nucleon of these nuclides is greater than those of their immediate
meighbours. Each of these nuclei can be formed by adding an alpha
particle to the preceding nucleus.
4. After A = 20, there is a gradual increase in B.E. per nucleon. The maximum
value of 8.8 MeV is reached at A = 56. Therefore, Iron nucleus is the most
stable.
5. Binding energy per nucleon of nuclides having mass numbers ranging from
40 to 120 are close to the maximum value. So, these elements are highly
stable and non-radioactive.
6. Beyond A = 120, the value decreases and falls to 7.6 MeV for Uranium.
7. Beyond A = 128, the value shows a rapid decrease. This makes elements
beyond Uranium (trans – uranium elements) quite unstable and radioactive.
8. The drooping of the curve at high mass number indicates that the nucleons
are more tightly bound and they can undergo fission to become stable.
9. The drooping of the curve at low mass numbers indicates that the nucleons
can undergo fusion to become stable.
Special Features:
17. Radioactivity:
Lead
Box
Radioactive
substance
α
β
γ
-
-
-
-
-
-
-
-
-
-
-
+
+
+
+
+
+
+
+
+
+
Radioactivity is the phenomenon of emitting
alpha, beta and gamma radiations
spontaneously.
Soddy’s Displacement Law:
1. ZYA
Z-2YA-4
α
2. ZYA
Z+1YA
β
3. ZYA
ZYA (Lower energy)
γ
Rutherford and Soddy’s Laws of Radioactive Decay:
1. The disintegration of radioactive material is purely a random process and
it is merely a matter of chance. Which nucleus will suffer disintegration, or
decay first can not be told.
2. The rate of decay is completely independent of the physical composition
and chemical condition of the material.
3. The rate of decay is directly proportional to the quantity of material
actually present at that instant. As the decay goes on, the original material
goes on decreasing and the rate of decay consequently goes on
decreasing.
18. If N is the number of radioactive atoms present at any instant, then the rate of
decay is,
dt
dN
- α N or
dN
dt
- = λ N
where λ is the decay constant or the disintegration constant.
Rearranging,
N
dN
= - λ dt
Integrating, loge N = - λ t + C where C is the integration constant.
If at t = 0, we had N0 atoms, then
loge N0 = 0 + C
loge N - loge N0 = - λ t
or loge (N / N0) = - λ t
or
N
= e- λt
N0
or N = N0 e- λ t
No.
of
atoms
(N)
N0
N0/2
N0/4
N0/8
N0/16
Time in half lives
0 T 2T 3T 4T
19. Radioactive Disintegration Constant (λ):
According to the laws of radioactive decay,
N
dN
= - λ dt
If dt = 1 second, then
N
dN
= - λ
Thus, λ may be defined as the relative number of atoms decaying per second.
Again, since N = N0 e- λ t
And if, t = 1 / λ, then N = N0 / e
or
N0
N
=
e
1
Thus, λ may also be defined as the reciprocal of the time when N / N0 falls to 1 / e.
20. Half – Life Period:
Half life period is the time required for the disintegration of half of the amount
of the radioactive substance originally present.
If T is the half – life period, then
N0
N
=
2
1
= e - λ T
e λ T = 2
(since N = N0 / 2)
λ T = loge 2 = 0.6931
T =
λ
0.6931
T
λ =
0.6931
or
Time t in which material changes from N0 to N:
t = 3.323 T log10 (N0 / N)
Number of Atoms left behind after n Half – Lives:
N = N0 (1 / 2)t/T
N = N0 (1 / 2)n
or
21. Units of Radioactivity:
1. The curie (Ci): The activity of a radioactive substance is said to be one
curie if it undergoes 3.7 x 1010 disintegrations per second.
1 curie = 3.7 x 1010 disintegrations / second
2. The rutherford (Rd): The activity of a radioactive substance is said to be
one rutherford if it undergoes 106 disintegrations per second.
1 rutherford = 106 disintegrations / second
3. The becquerel (Bq): The activity of a radioactive substance is said to be
one becquerel if it undergoes 1 disintegration per second.
1 becquerel = 1 disintegration / second
1 curie = 3.7 x 104 rutherford = 3.7 x 1010 becquerel
Nuclear Fission:
Nuclear fission is defined as a type of nuclear disintegration in which a heavy
nucleus splits up into two nuclei of comparable size accompanied by a
release of a large amount of energy.
0n1 + 92U235 → (92U236) → 56Ba141 + 36Kr92 +30n1 + γ (200 MeV)
22. Chain Reaction:
n = 1
N = 1
n = 2
N = 9
n = 3
N = 27
Neutron (thermal) 0n1
Uranium 92U235
Barium 56Ba141
Krypton 36Kr92
n = No. of fission stages
N = No. of Neutrons
N = 3n
23. Chain Reaction:
n = 1
N = 1
n = 2
N = 9
n = 3
N = 27
Critical Size:
For chain reaction to occur, the
size of the fissionable material
must be above the size called
‘critical size’.
A released neutron must travel
minimum through 10 cm so that it
is properly slowed down (thermal
neutron) to cause further fission.
If the size of the material is less
than the critical size, then all the
neutrons are lost.
If the size is equal to the critical
size, then the no. of neutrons
produced is equal to the no. of
neutrons lost.
If the size is greater than the
critical size, then the reproduction
ratio of neutrons is greater than 1
and chain reaction can occur.
24. Nuclear Fusion:
Nuclear fusion is defined as a type of nuclear reaction in which two lighter
nuclei merge into one another to form a heavier nucleus accompanied by a
release of a large amount of energy.
Energy Source of Sun:
Proton – Proton Cycle:
1H1 + 1H1 → 1H2 + 1e0 + 0.4 MeV
1H1 + 1H2 → 2He3 + 5.5 MeV
2He3 + 2He3 → 2He4 + 2 1H1 + 12.9 MeV
Carbon - Nitrogen Cycle:
6C12 + 1H1 → 7N13 + γ (energy)
7N13 → 6C13 + 1e0 (positron)
Energy Source of Star:
6C13 + 1H1 → 7N14 + γ (energy)
7N14 + 1H1 → 8O15 + γ (energy)
8O15 → 7N15 + 1e0 (positron)
7N15 + 1H1 → 6C12 + 2He4 + γ (energy)
End of Atomic Nucleus