What is Atomic physics?
'''Atomic physics''' is the field of [[physics]] studying atoms as an isolated system of [[Electron|electrons]] and an [[Atomic nuclei|atomic nucleus]]. It is primarily [[wikt:concerned|concerned]] with the [[Electron configuration|arrangement of electrons within the atom]] and the [[wikt:process|processes]] by which it changes. This includes [[Ion|ions]] as well as [[wikt:neutral|neutral]] atoms.{{cn|date=December 2024}} The term ''atomic physics'' is often [[wikt:associated|associated]] with [[nuclear power]] and [[Nuclear weapon|nuclear bombs]], due to the [[wikt:synonymous|synonymous]] use of ''atomic'' and ''nuclear'' in [[standard English]]. However, physicists [[wikt:distinguish|distinguish]] between atomic physics, which deals with the atom as a system [[wikt:consist|consisting]] of a [[Atomic nucleus|nucleus]] and electrons, and [[nuclear physics]], [[wikt:deem|deeming]] [[Atomic nucleus|atomic nuclei]] alone.{{cn|date=December 2024}} As with many scientific fields, [[wikt:strict|strict]] [[wikt:delineation|delineation]] can be highly [[wikt:contrived|contrived]] and atomic physics is often considered in the wider [[Context (language)|context]] of atomic, molecular and [[wikt:optical|optical]] physics. Physics' [[research]] groups are usually so [[wikt:classified|classified]].{{clarification|date=December 2024}}{{cn|date=December 2024}} ==Isolated atoms== Atomic physics often considers atoms one by one. Atomic models will consist of a single nucleus that may be surrounded by one or more bound electrons. It is not concerned with the formation of [[Molecule|molecules]], though much of the physics is [[wikt:identical|identical]], nor does it [[wikt:examine|examine]] atoms in a [[Solid state physics|solid state]] as [[condensed matter]]. It is concerned with processes such as [[ionization]] and [[Excited state|excitation]] by [[Photon|photons]] or [[Collision|collisions with atomic particles]]. While modelling atoms in isolation may not seem [[wikt:realistic|realistic]], if one considers atoms in a [[gas]