23.2.4—Half-life

define half-life.

Use —half-life to connect the rule to the data and decision in the question.

This matters because —half-life determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —half-life to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Half-life is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.