Spin (physics) Spin (physics) In quantum mechanics and particle physics, spin is an intrinsic form of angular momentum carried by elementary particles, composite particles (hadrons), and atomic nuclei. Spin is one of two types of angular momentum in quantum mechanics, the other being "orbital angular momentum". The orbital angular momentum operator is the quantum-mechanical counterpart to the classical angular momentum of orbital revolution and appears when there is periodic structure to its wavefunction as the angle varies. The existence of spin angular momentum is inferred from experiments, such as the Stern–Gerlach experiment, in which silver atoms were observed to possess two possible
Nuclear Power and the Environment radiation to aid in later chapters. The first half covers the basics on atoms such as: an atom consists of Neutrons, Protons, and Electrons; the atomic number of an atom determines the amount of protons in one atom; and that protons are roughly 2000 times heavier than electrons (see atom). The concept of radiation is introduced through ionization which is the process of adding one or more electrons to, or removing one or more electrons from, atoms or molecules, thereby creating ions. From there certain particles can cause ionization. The ionizing particles are alpha particles (a type of ionizing radiation