Isolated Atoms
Atomic physics always considers atoms in isolation. 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 molecules (although much of the physics is identical), nor does it examine atoms in a solid state as condensed matter. It is concerned with processes such as ionization and excitation by photons or collisions with atomic particles.
While modelling atoms in isolation may not seem realistic, if one considers atoms in a gas or plasma then the time-scales for atom-atom interactions are huge in comparison to the atomic processes that are generally considered. This means that the individual atoms can be treated as if each were in isolation, as the vast majority of the time they are. By this consideration atomic physics provides the underlying theory in plasma physics and atmospheric physics, even though both deal with very large numbers of atoms.
Read more about this topic: Atomic Physics
Famous quotes containing the words isolated and/or atoms:
“Literature is not exhaustible, for the sufficient and simple reason that a single book is not. A book is not an isolated entity: it is a narration, an axis of innumerable narrations. One literature differs from another, either before or after it, not so much because of the text as for the manner in which it is read.”
—Jorge Luis Borges (1899–1986)
“It is the way unseen, the certain route,
Where ever bound, yet thou art ever free;
The path of Him, whose perfect law of love
Bids spheres and atoms in just order move.”
—Jones Very (1831–1880)