This revised edition narrates the brief history of the people, the events, and the ideas that advanced mankind into the electrical, nuclear, and space ages. The book describes the basic concepts of Quantum Mechanics and the efforts made to decipher the secrets of the structure of atoms, molecules, crystals and elementary nuclear particles. The author emphasizes the inherent limitations of classical mechanics that led to paradoxical outcome of the special theory of relativity, which in turn infected Dirac's attempts to rehabilitate the Schrodinger's Quantum Wave Equations. During the hundred and ten odd years of its existence, Quantum Mechanics has passed through three distinct stages of development. The first stage began by Planck's quanta and ended de Broglie's matter waves. It could be properly described as the stage of structuring the electronic shells of the atom. The second stage in the development of Quantum Mechanics began with de Broglie's discovery of matter waves, in 1924 and ended with the end of WWII. It could be properly described as the stage of deciphering the nuclear forces of the atomic core. The theory of the nucleus of the atom was created and new elementary particles were discovered that revealed some of the secrets of the nuclear forces. The third period began after World War II with the invention of nuclear reactors, radiospectrometers, and high altitude flights. This stage could be properly described as the phase of high energy exploration of the nuclear elementary particles. During this stage, Quantum Mechanics come up against ever greater difficulties, setbacks and failures. The newly discovered behaviors of elementary particles and their interactions shook the foundation of the old laws upon which Quantum Mechanics was erected. CHAPTER 1: THE ROAD TO THE ATOM: 1792-1900 The Creation from Nothing The Road to Conservation Newton Laws of Conservation Beginning of the Steam Age The French Revolution Birth of Electricity Nobel's Incentive Landmarks of the Nineteenth Century Ethereal Space Light Spectrum of Elements Discovery of the Electron Thomson Model of the Atom Lorentz Transformation Discovery of X-rays Discovery of Radioactivity Classical Senses and Cannons Birth of Quantum Mechanics Thermal Radiation Black Body Radiation Boltzmann-Wien Laws Rayleigh-Jeans Law CHAPTER 2: THE BIRTH OF THE QUANTA Thermal Radiation at High Frequencies The Quanta Photons and Corpuscles Discovery of Photons Dual Nature of Light Rutherford Atom Model Bohr Atom Model Privileged Atomic Quantum Orbits Emission and Absorption of Radiation Brightness and Spin of Emitted Radiation de Broglie Matter Waves Dual Properties of Electrons Electron Diffraction Quantum Wave Theory Probability Wave Function Uncertainty Relation Tunnel Effect Schrodinger Equation Harmonic Oscillator Pauli's Exclusion Principle The Spin Electronic Architecture of the Atom Periodic Table of Elements Atomic Spectrum CHAPTER 3: MOLECULES AND SOLIDS Molecules Ionic molecule Covalent molecules. Quantum Mechanics of Solids Compound crystals Metallic crystals Stark Effect Molecular Levels of Energy Insulators Conduction in Metal Superconductivity Semiconductors CHAPTER 4: THE INTERIOR OF THE NUCLEUS Radioactivity The Nucleus of the Atom The Neutron Nuclear Forces Discovery of the Meson Nuclear Stability and Abundance Alpha Particle Decay Nuclear Energy Levels Gamma Ray Decay Nuclear Fission Beta Particles Decay The Discovery of the Neutrino Electron Capture CHAPTER 5: ELEMENTARY NUCLEAR PARTICLES Relativistic Quantum Mechanics Dirac's Quantum Wave Equations Discovery of Anti-matter Action at a Distance Field and Matter Decay of Subatomic Particles Deduction of Coulomb's Law Classification of Elementary Particles Decay of Elementary Particles CHAPTER 6: CRITIQUE ON QUANTUM MECHANICS Critique on the Special Theory of Relativity Critique on the Theory of Matter Waves CHAPTER 7: CONTRIBUTION BY NATIONS OF SCIENTISTS CHAPTER 8: MAIN FACTS"