When atoms emit light in an electric field, there is an effect known as the Stark effect. The Stark effect is the splitting and shifting of spectral lines in the presence of an electric field. This phenomenon occurs due to the interaction between the electric field and the charged particles within the atom, primarily the electrons.
The Stark effect arises from two main mechanisms: the linear Stark effect and the quadratic Stark effect.
Linear Stark Effect: In the linear Stark effect, the energy levels of the atom are shifted by the electric field, resulting in the splitting of spectral lines. This shift is proportional to the strength of the electric field. The magnitude of the energy shift depends on the quantum numbers associated with the energy levels. For example, in hydrogen, the energy levels associated with the principal quantum number (n) are shifted, leading to the splitting of spectral lines.
Quadratic Stark Effect: The quadratic Stark effect refers to the change in the intensity or broadening of spectral lines due to the presence of an electric field. This effect arises from the interaction between the electric field and higher-order terms in the perturbation expansion of the energy levels.
Both the linear and quadratic Stark effects can be observed in various atomic systems. The extent of the effect depends on factors such as the strength of the electric field, the quantum numbers of the energy levels involved, and the specific characteristics of the atom or molecule.
It's worth noting that the Zeeman effect, as you mentioned in your question, is specifically related to the interaction between atoms and a magnetic field, leading to the splitting and shifting of spectral lines. The Stark effect, on the other hand, is associated with the influence of an electric field on the energy levels and spectral lines of atoms. Both effects are significant in understanding the behavior of atoms in different external fields and have important applications in spectroscopy and the study of atomic and molecular structure.