(a) A radioactive source emits alpha (α), beta (β) and gamma (γ) radiation.

(i) Which two types of radiation will pass through a sheet of card?

(1 mark)

(ii) Which two types of radiation would be deflected by an electric field?

(1 mark)

(iii) Which type of radiation has the greatest range in air?

(1 mark)

(b) A student suggests that the radioactive source should be stored in a freezer at –20 °C.

The student thinks that this would reduce the radiation emitted from the source.

Suggest why the student is wrong.

(1 mark)

(c) Phosphorus-32 is a radioactive isotope that emits beta radiation.

(i) How is an atom of phosphorus-32 different from an atom of the stable isotope phosphorus-31?

(1 mark)

(ii) The graph shows how the count rate of a sample of phosphorus-32 changes with time.

Use the graph to calculate the half-life of phosphorus-32.

Show clearly how you used the graph to obtain your answer.

Half-life = ………………………… days
(2 marks)

(iii) Plants use phosphorus compounds to grow. Watering the root system of a plant with a solution containing a phosphorus-32 compound can help scientists to understand the growth process.

Explain why phosphorus-32 is suitable for use as a tracer in this situation.

(2 marks)

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From Q4 P1 AQA January 2008 but now on P2 syllabus