Irradiation & contamination

Describe one similarity and one difference between a nucleus of iodine-127 and a nucleus of iodine-131.

Iodine-131 is radioactive.

The graph shows how the activity of a sample of iodine-131 changes over time.

Use the graph to show that the half-life of iodine-131 is approximately 8 days.

Show your working on the graph.

Iodine-131 is used as a medical tracer and for radiotherapy when treating cancer patients.

A radiologist injects a patient with a dose of iodine-131. The dose has an initial activity of 4.00 MBq.

Calculate the number of days it takes the activity to reduce to 0.25 MBq.

The radiologist wears gloves and a film badge while handling iodine-131.

The film badge contains photographic film which turns dark when exposed to ionising radiation.

Explain how using the gloves and the film badge reduces risks to the radiologist’s health.

A scientist is working with a radioactive material. The radioactive material emits beta radiation.

Fig. 16.1 shows the scientist walking very close to the radioactive material.

Fig. 16.1

Describe the effect of the radioactive material on the scientist as they walk past.

Tick (✓) one box.

In Fig. 16.2, the scientist knocks the radioactive material onto the floor. They pick up the radioactive material with their bare hands.

Fig. 16.2

Describe the effect of the radioactive material on the scientist as they pick it up.

Tick (✓) one box.

Fig. 16.3 shows the scientist standing behind a lead screen and a lead-glass window. They use a robotic arm to handle the radioactive material.

Fig. 16.3

Describe the effect of the radioactive material on the scientist when they are behind the lead screen.

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A scientist is working with a radioactive material. The radioactive material emits beta radiation.

Fig. 11.1 shows the scientist walking very close to the radioactive material.

Fig. 11.1

Describe the effect of the radioactive material on the scientist as they walk past.

Tick (✓) one box.

In Fig. 11.2, the scientist knocks the radioactive material onto the floor. They pick up the radioactive material with their bare hands.

Fig. 11.2

Describe the effect of the radioactive material on the scientist as they pick it up.

Tick (✓) one box.

Fig. 11.3 shows the scientist standing behind a lead screen and a lead-glass window. They use a robotic arm to handle the radioactive material.

Fig. 11.3

Describe the effect of the radioactive material on the scientist when they are behind the lead screen.

Tick (✓) one box.

This question is about two radioactive isotopes, X and Y.

Isotope X gives out gamma rays.

The charge on the nucleus of isotope X stays the same.

What happens to the mass number of the nucleus?

Isotope X is stored safely in a container.

Suggest a material for the container.

Describe how an object can be irradiated using isotope X.

Equal amounts of isotope Y are placed in a plastic box and in a cardboard box.

Table 11.1 gives information about both boxes.

Which box is best for storing isotope Y ?

Give one reason for your answer using the information in Table 11.1.

The plastic box does not let any of the radiation emitted by isotope Y pass through it.

Which type of radiation does isotope Y emit?

The graph shows how the quantity of isotope Y changes with time.

Complete Table 11.2 using the graph to help you.

Explain why the half-life of isotope Y is 5 days.

X and Y are radioactive isotopes. They emit either alpha particles or beta particles.

Complete Table 14.1 to show what happens to a nucleus of an atom when an alpha particle or a beta particle is emitted.

A scientist measures the half-life of isotope X.

They measure the half-life three times.

Why do they get a slightly different result each time?

After 18 days, the ratio of the activity of X to the initial activity of X is 1:4.

Calculate the half-life of isotope X.

Isotope X only gives out beta particles. Isotope Y only gives out alpha particles.

The scientist measures the activity of one of the isotopes using a Geiger counter.

They then place a material between the isotope and the Geiger counter and record the reading.

Table 14.2 shows their results:

Which isotope are they using?

Give two reasons for your answer.

The scientist accidentally places isotope X close to isotope Y.

Explain why isotope Y is irradiated, but not contaminated, by isotope X.

Nuclear power is non-renewable and the plants can produce nuclear waste.

Suggest two reasons why some countries still use nuclear power.

Radioactive elements can contaminate or irradiate objects.

Which statement describes irradiation?

A Radiation from outside your body travels into your body.

B Radioactive material is on the skin.

C Radioactive material is breathed in.

D Radioactive material is eaten.