recoil

in radioanalytical chemistry
https://doi.org/10.1351/goldbook.R05200
The motion acquired by a particle through a collision with, or the emission of, another particle or electromagnetic radiation.
Source:
PAC, 1994, 66, 2513. 'Nomenclature for radioanalytical chemistry (IUPAC Recommendations 1994)' on page 2524 (https://doi.org/10.1351/pac199466122513)