Editing Nuclear reaction (section)

{{Short description|Transformation of a nuclide to another}}
[[File:Li6-D Reaction.svg|300 px|thumb|In this symbolic representing of a nuclear reaction, [[lithium-6]] ({{nuclide|Lithium|6}}) and [[deuterium]] ({{nuclide|Hydrogen|2}}) react to form the highly excited intermediate nucleus {{nuclide|Beryllium|8}} which then decays immediately into two [[alpha particle]]s of [[helium-4]] ({{nuclide|helium|4}}). [[Proton]]s are symbolically represented by red spheres, and [[neutron]]s by blue spheres.]]

{{Nuclear physics}}

In [[nuclear physics]] and [[nuclear chemistry]], a '''nuclear reaction''' is a process in which two [[atomic nucleus|nuclei]], or a nucleus and an external [[subatomic particle]], collide to produce one or more new [[nuclide]]s. Thus, a nuclear reaction must cause a transformation of at least one nuclide to another. If a nucleus interacts with another nucleus or particle, they then separate without changing the nature of any nuclide, the process is simply referred to as a type of nuclear [[scattering]], rather than a nuclear reaction.

In principle, a reaction can involve more than two [[particle]]s [[collision|colliding]], but because the probability of three or more nuclei to meet at the same time at the same place is much less than for two nuclei, such an event is exceptionally rare (see [[triple alpha process]] for an example very close to a three-body nuclear reaction). The term "nuclear reaction" may refer either to a change in a nuclide '''induced''' by collision with another particle or to a '''spontaneous''' change of a nuclide without collision.

Natural nuclear reactions occur in the interaction between [[cosmic ray]]s and matter, and nuclear reactions can be employed artificially to obtain nuclear energy, at an adjustable rate, on-demand. [[Nuclear chain reaction]]s in [[fissionable]] materials produce induced [[nuclear fission]]. Various [[nuclear fusion]] reactions of light elements power the energy production of the [[Sun]] and stars. Most nuclear reactions (fusion and fission) results in transmutation of nuclei (called also [[nuclear transmutation]]).