The first is that atoms interact with magnetic fields, and there are always magnetic fields about.
When an atom interacts, then energy can be emitted or absorbed.
However, atoms interact with each other, and there is a tendency for some to gain electrons at the expense of others.
The former often helps one detect periodicity in specimens, while the latter (although more difficult to achieve) is key to visualizing how individual atoms interact.
Further, these atoms interact with each other and their environment in unknown ways.
It affects how the atom interacts with its neighbors.
Associative ionization is a gas phase reaction in which two atoms or molecules interact to form a single product ion.
When atoms interact to form a chemical bond, the atomic orbitals are said to mix in a process called orbital hybridisation.
Though the atom and the laser pulse interact in various ways, this is ignored here (see high harmonic generation instead).
The atom interacts with a single-mode field confined to a limited volume V in an optical cavity.