Subatomic particle is the total number of nucleons (neutrons and protons collectively). Chemistry concerns itself with how electron sharing binds atoms into structures such as crystals and molecules. Nuclear physics deals with how protons and neutrons arrange themselves in nuclei. The study of subatomic particles, atoms and molecules, and their structure and interactions, requires quantum mechanics. Analyzing processes that change the numbers and types of particles requires quantum field theory. The study of subatomic particles "per se" is called particle physics. The term "high-energy physics" is nearly synonymous to "particle physics" since creation of particles requires high energies: it occurs only as
Ugo Fano Fano spent 1936–37 with Werner Heisenberg in Leipzig. In 1939, he married Camilla Lattes, also known as "Lilla", a teacher who would collaborate with him in a well-known book on atomic and molecular physics, "Physics of Atoms and Molecules" (1959). Appendix III of this book presents an elementary description of the collision of two charged particles, which was used by Richard Feynman in lectures that have been published as "". An expanded version of this book was subsequently published as "Basic Physics of Atoms and Molecules" (1972). Later that year, he immigrated to the United States due to increasing antisemitic