24.3.1—A tracer is a substance containing radioactive nuclei that can be introduced

understand that a tracer is a substance containing radioactive nuclei that can be introduced into the body and is then absorbed by the tissue being studied.

Use —a tracer is a substance containing radioactive nuclei that can be introduced to connect the rule to the data and decision in the question.

This matters because —a tracer is a substance containing radioactive nuclei that can be introduced determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —a tracer is a substance containing radioactive nuclei that can be introduced to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —A tracer is a substance containing radioactive nuclei that can be introduced is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.