Chapter 2. The Bohr Atom

G. C. Ghirardi

J. D. Main Smith

Z. Ficek

This chapter illustrates Niels Bohr's ideas in some detail. In the formulation of his model, Bohr assumed that the electron in the hydrogen atom moves under the influence of the Coulomb attraction between it and the positively charged nucleus, as assumed in classical mechanics. The Bohr model was very successful in explaining the discrete atomic spectra of one-electron atoms. The Bohr model is, of course, a theoretical model of an atom. Using Bohr's quantization postulate, find the linear velocity of the electron's sphere. To find the radius of the orbit, Bohr postulated that the angular momentum of the electron is quantized, i.e., it can only take values that are integer multiples of ħ. The chapter begins with considering the classical equation of motion for the electron in a circular orbit, which is based on Newton's laws of motion and Coulomb's law of electric force.

Л. И. Пономарев

1. Origins - Chapter One: Atoms Waves Quanta Before and after Democritus Titus Lucretius Carus Isaac Newton on atoms. Chapter Two: Spectra Ions Radiant matter Atoms, electrons, waves Discovery of spectral analysis The beginnings of television William Crookes Kinetic theory of gases Mikhail Vasilyevich Lomonosov. Chapter Three: The planetary atom Spectral series Photons Victory of atomistics The indivisible atom The diffraction grating Just what hath Rutherford wrought? Light pressure Chapter Four: Pre-Bohr times The Bohr atom Post-Bohr times Formal model of the atom Niels Henrik David Bohr Experimental proof of Bohr's postulates. Chapter Five: Teachings of the Ancients First attempts Elements and atoms Table of elements The Periodic law Atoms and people. 2. Ideas - Chapter Six: Contemporaries comment on Bohr's theory Phenomenon, image, concept, formula Heisenberg's matrix mechanics The foundation of physics. Chapter Seven: Louis de Broglie Matter waves Optical-mechanical analogy Schrodinger's wave mechanics The life of Boscovich ... ... and his atom Paul Ehrenfest (1880-1933). Chapter Eight: Schrodinger's equation The meaning of the psi function The image of the atom Quantum truth Compton's experiment Electron diffraction. Chapter Nine: Wave-particle duality Uncertainty relation Complementarity principle Duality and uncertainty Poets and the complementarity principle. Chapter Ten: Heads or tails and target shooting Electron diffraction Probability waves Electron waves The atom and probability Probability and atomic spectra Causality and chance, probability and certainty People, events, quanta. Chapter Eleven - What is an atom? What is quantum mechanics? Physical reality In search of the last concepts. 3. Results - Chapter Twelve: Wilhelm Konrad Rontgen Antoine Henri Becquerel Pierre and Marie Curie Ernest Rutherford and Frederick Soddy The energy of radium X-ray waves. Chapter Thirteen: The chemisty of radioelements Isotopes uranium family Stable isotopes Radioactive decay energy Nuclear binding energy Uranium Earth and radium Knights of the fifth decimal place. Chapter Fourteen: Probing into the nucleus The neutron Artificial radioactivity Slow neutrons Nuclear fission Letters about fission. Chapter Fifteen: Tunnel effect Effective cross-sections of reactions Neutron cross-sections Nuclear fission Labelled atoms Radiocarbon dating. Chapter Sixteen: Chain reaction Nuclear reactor Spontaneous fission of uranium The natural nuclear reactor at Oklo. Chapter Seventeen: Atomic Energy Plutonium The atomic bomb The atomic problem A chronology of the atomic era Soddy on atomic energy. Chapter Eighteen: Solar light Crucibles of elements The fate of the Sun The Sun, life and chlorophyll Life under the Sun A sun on earth Quanta around us. 4. Reflections - Chapter Nineteen: Inception of the scientific method Essence of the scientific method and its development. Truth and completeness of the scientific picture of the world. Science and humanity Boundaries of the scientific method Science and art Future of science Epilogue.