In [[atomic physics]] and [[chemistry]], an '''atomic electron transition''' (also called an '''electronic (de-)excitation''', '''atomic transition''', or '''quantum jump''') is a change (or jump) of an [[electron]] changing from one [[energy level]] to another within an [[atom]]<ref>Schombert, James. [http://abyss.uoregon.edu/~js/cosmo/lectures/lec08.html "Quantum physics"] University of Oregon Department of Physics</ref> or [[artificial atom]].<ref>{{Cite journal |arxiv = 1009.2969|bibcode = 2011PhRvL.106k0502V|title = Observation of Quantum Jumps in a Superconducting Artificial Atom|journal = Physical Review Letters|volume = 106|issue = 11|pages = 110502|last1 = Vijay|first1 = R|last2 = Slichter|first2 = D. H|last3 = Siddiqi|first3 = I|year = 2011|doi = 10.1103/PhysRevLett.106.110502|pmid = 21469850| s2cid=35070320 }}</ref> It appears discontinuous as the electron "jumps" from one quantized energy level to another, typically in a few [[nanosecond]]s or less.
Electrons jumping to energy levels of smaller n emit electromagnetic radiation in the form of a photon. Electrons can also absorb passing photons, which drives a quantum jump to a level of higher n. The larger the energy separation of the states between which the electron jumps, the shorter the [[wavelength]] of the photon emitted.<ref name=":0" />
