In chemistry, nuclear physics, and particle physics, inelastic scattering is a process in which the kinetic energy of a particle or a system of particles changes after a collision. Formally, the kinetic energy of the incident particle is not conserved (in contrast to elastic scattering). In an inelastic scattering process, some of the energy of the incident particle is lost or increased.  Although inelastic scattering is historically related to the concept of inelastic collision in dynamics, the two concepts are quite distinct; inelastic collision in dynamics refers to processes in which the total macroscopic kinetic energy is not conserved. In general, scattering due to inelastic collisions will be inelastic, but, since elastic collisions often transfer kinetic energy between particles, scattering due to elastic collisions can also be inelastic, as in Compton scattering meaning the two particles in the collision transfer energy causing a loss of energy in one particle.