In this post, we will see the book titled Physics of the Microworld by K. I. Shcholkin. The book is an introduction to many facets of the quantum phenomena, both basic and advanced. The book is essentially a collection of a variety of essays on the theme of the quantum physics.About the bookThe back cover of the book describes the books as:In these sketches, the late K. I. SHCHOLKIN, Corresponding Member of the USSR Academy of Sciences, gives a popular account of the structure of the atoms and atomic nuclei of matter and anti­ matter, of nuclear forces and the structure of nucleons. His book tells about strong and weak interactions, parity and its non-conservation, and vacuum polarization. Models of nuclei, nuclear fission, and fusion reactions are described, with basic information on elementary particles, and the latest technical advances of quantum physics (maser amplifiers, hydrogen-atom radiation, Mossbauer effect, etc.). There are also articles devoted to strange particles like K-mesons.The book is in a clear and readable manner, and is intended for sixth-formers and general non-technical readers who are interested in the latest developments in nuclear and atomic physics, i.e. the physics of the microworld.The book has had three editions in Russian and has been translated into Spanish.There is an interesting essay on Negative absolute temperatures (p. 174)!The book was first published by Mir in 1974 and was translated from the Russian by Michael Zimmerman.Contents Hydrogen atom. Quantum numbers 7Hydrogen atom spectrum 17Magnetic moments 22Basic principles of quantum mechanics 32Radio emission of hydrogen on the 21.1-cm wavelength 36Deuterium, tritium, neutron 42Positron, antiproton, antineutron, antihydrogen 45Heavy nuclei 58Characteristic dimensions of particles 63Nuclear forces. Pi-mesons (pions). 67Uncertainty relation and virtual processes 71Nuclear forces (continued). 78Virtual processes and nucleon structure 93Strong, electromagnetic, and weak interactions 98Parity, its conservation and non-conservation 106Polarization of vacuum 114List of elementary particles playing a definite role in the structure of matter 121Photon 121Leptons 125Neutrino 126Muons 138Electron shells 144Quantum amplifiers (masers and lasers) 155C02 laser 166Semiconductor lasers 170Negative absolute tem peratures. 174Nuclear synthesis reactions 179Liquid-drop nuclear model and fission reactions 186Shell model of nucleus 189Mossbauer effect 193Complete list of elementary particles 205Isotopic spin 209Strangeness 215G-parity 219K-mesons 221Hyperons 226Resonances 231Table of mesons and mesic resonances. 237Table of baryons and baryonic resonances 245On the classification of hadrons 251Unitary symmetry. Gell-Mann-Ne’eman model 254Quarks 269Formula for particle masses in unitary multiplet 279Hyperfragments 283Basic physical magnitudes in the SI system. 289Conversion table 290