A reaction involving an atomic nucleus. It is usually initiated by bombarding a target nucleus with a radiation, called a projectile. The interaction of the radiation with the nucleus may cause the emission of other radiations, called ejectiles. In the reaction 14N + n â†’ 14C + p, the target nucleus is 14N, the neutron is the projectile, and the proton is the ejectile. This reaction can also be written as 14N(n,p)14C. Related to chemical reaction. Related to reaction.
In nuclear physics, a nuclear reaction is a process in which two nuclei or nuclear particles collide, to produce different products than the initial particles. In principle a reaction can involve more than two particles colliding, but such an event is exceptionally rare. If the particles collide and separate without changing, the process is called an elastic collision rather than a reaction.