A nuclear reaction involves the rearrangement of the nuclear constituents.
In all nuclear processes, the following quantities are conserved:
- nucleon number
- proton number (charge)
- mass-energy
- momentum
Induced nuclear reactions occur when a nucleus changes as a result of being struck by a particle.
If the products have greater mass than the reactants (nucleus and incident particle) before the reaction, then the incident particle must supply enough kinetic energy to make up for the increase in mass of the products to allow a reaction to take place.