Physics 9702 · AS & A Level · PET scanning

PET scanning — practice question

Fluorine-18 ($^{18}_{9}\text{F}$) undergoes beta-plus ($\beta^{+}$) decay and has a half-life of 110 minutes.
(a(i))[1]

State the name given to the beta-plus particle.

(a(ii))[1]

Show that the decay constant of fluorine-18 equals $1.05 \times 10^{-4}\,\text{s}^{-1}$.

(a(iii))[3]

Determine the activity for $2.1 \times 10^{-12}\,\text{kg}$ of fluorine-18.

(b(i))[3]

Describe how the interaction between a $\beta^{+}$ particle and an electron in the body makes image formation possible.

(b(ii))[2]

Suggest why 110 minutes is an appropriate half-life for a nuclide used as a tracer in medical diagnosis.

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: the positron

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI