Tracer A stable, easily detected substance or a radioisotope added to a material to follow the location of the substance in the environment or to detect any physical or chemical changes it undergoes.
(a radioisotope; added; to a material; to follow the location of the substance in the environment or to detect any physical or chemical changes) (any physical or chemical changes; undergoes; )
a radioisotope any physical or chemical changes
added undergoes
to a material to follow the location of the substance in the environment or to detect any physical or chemical changes