Elementary Particles deals with the physics of elementary particles such as protons, neutrons, electrons, and photons. Topics covered include the prediction and discovery of new elementary particles; nucleons and pions; beta-disintegration and the discovery of the neutrino; and the problem of non-conservation of parity. The discovery of ""abandoned and strange"" particles called resonons is also discussed. This book is comprised of six chapters and begins with an overview of atomic physics and elementary particles, followed by an analysis of the prediction and discovery of new elementary particles such as the positron. The next chapter is devoted to the question of nuclear forces, with emphasis on nucleons and pions. Experiments in which protons and neutrons were bombarded with electrons are described. Subsequent chapters explore beta-disintegration and the discovery of the neutrino, along with the problem of non-conservation of parity. The final chapter considers elementary particles known as resonons, which exhibit a strange behavior and were discovered in the region of high energies. This monograph will be a valuable resource for physicists as well as students and researchers in atomic physics.