Radioactive decay & nuclear radiation

There are different isotopes of the element carbon.

When carbon-14 decays into nitrogen-14, it emits beta radiation.

Complete the equation for the decay of carbon-14.

Carbon-14 has a half-life of 5700 years.

Explain what half-life means.

Alpha particles, beta particles, and gamma rays can penetrate different types and thicknesses of material.

Draw one line from each type of radiation to the type and maximum thickness of material radiation is able to penetrate.

Type of radiation
Type and maximum thickness of material

This question is about radioactivity.

Some atoms and isotopes of elements are shown.

Which statements are correct for these atoms and isotopes? Tick (✓) three boxes.

Thorium‑234 decays by emitting beta radiation.

What happens to the mass number and charge of a nucleus of thorium‑234 when it decays?

Draw one line from each quantity to what happens.

Why do some atoms emit nuclear radiation?

The diagram shows how the amount of a radioactive element changes over a total of 30 days.

Calculate the half‑life of this radioactive element.

When uranium‑238 decays, it forms isotopes of different elements.

The graph shows part of the decay chain produced when uranium‑238 decays.

Circle two points on the graph which are isotopes of the same element.

Explain how you worked out your answer.

(b) Describe what happens to the atomic number and mass of a nucleus of²³⁴Th as it decays into (i) ²³⁴Pa.

Which type of radiation is emitted when²³⁴Th decays into²³⁴Pa? (ii)

Eventually the isotope²⁰⁶Pb is formed and the decay chain stops. (d)

Explain why the decay chain stops at²⁰⁶Pb.

13* Alpha, beta and gamma radiation have different penetrating powers.

A teacher investigates whether a radioactive source is emitting alpha, beta or gamma radiation.

They place different types of screens between the source and a Geiger-Mϋller tube.

The diagram shows the teacher’s experiment.

The table shows the data the teacher collects.

Use the table to explain which type of nuclear radiation is emitted by the source.

Describe some other differences between alpha, beta and gamma radiation.

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.

A scientist measures the activity of a radioactive isotope. She uses a Geiger-Muller tube connected to a counter.

Table 12.1 shows her results.

What is the mean activity of the isotope?

Is there a pattern in the results in Table 12.1 ?

Explain your answer using ideas about radioactivity.

Carbon-12 is a stable isotope. Carbon-14 is an unstable radioactive isotope.

Table 12.2 shows the contents of each nucleus.

Explain why carbon-12 and carbon-14 are isotopes.

This is the equation for the radioactive decay of carbon-14:

What happens to the nuclear mass (mass number) when carbon-14 decays?

Americium-241 is a radioactive isotope used in smoke alarms.

Table 12.3 shows how the activity of americium-241 changes.

What is meant by the half-life of an isotope?

Use the data in Table 12.3 to calculate the half-life of americium-241.

This is a diagram of a smoke alarm.

Smoke enters the smoke alarm, which blocks the radiation emitted by the americium-241.

A smoke alarm company decides to use a different isotope.

Table 12.4 shows the three choices of isotope.

Which isotope, A, B or C, is the best to use in a smoke alarm?

Tick (✓) one box.

Explain your answer using the information in Table 12.4.

A radioactive isotope emits only gamma rays.

A teacher places different materials in front of the isotope. She measures the reading on a Geiger-Muller tube connected to a counter.

Which row in the table shows the correct reading on the counter?

Carbon-12 is a stable isotope. Carbon-14 is an unstable radioactive isotope.

Describe what is meant by the term isotope.

This is the equation for the radioactive decay of carbon-14:

Which type of radiation is emitted by carbon-14?

Describe how the mass and charge of the nucleus changes when the carbon-14 decays.

Mass........

Charge........

Carbon-14 can be used to date ancient objects.

An ancient object is 17 100 years old. The half-life of carbon-14 is 5700 years.

For the ancient object, what is the ratio of the original amount of carbon-14 to the amount of carbon-14 left?

This question is about radioactive atoms.

Why are some atoms radioactive?

Phosphorus-32 (³²₁₅P) gives out beta particles.

Complete the equation for the beta decay........

Phosphorus-32 only gives out beta particles.

Describe a simple experiment to show how this can be demonstrated in a laboratory.

You may include a diagram in your answer.

Beta particles are one type of radioactive particle.

Name a different particle given out by radioactive atoms.

Look at the diagram. It compares the model of the atom today with a model of the atom in 1902.

Model of the atom today
Model of the atom in 1902

Describe two differences between the models in the diagram.

Explain why the model of the atom has changed over time.

This question is about different types of radiation.

An isotope emits one type of radiation. It could be alpha, beta or gamma.

Describe how a teacher could show the type of radiation emitted using school equipment.

You may include a diagram in your answer.

Describe how these atoms can emit radiation.

What type of radiation is emitted?

An element gives out a beta () particle.

The table shows how the atomic number and mass number of the element change.

Which row of the table is correct?

This question is about radioactivity.

A teacher shows his class an experiment. The teacher wants to identify the type of radiation given out by a radioactive isotope.

He uses a Geiger-Muller tube connected to a counter to measure the count rate.

He places different materials between the radioactive isotope and the Geiger-Muller tube.

The table shows the count rate for different materials.

Suggest why the teacher places lead around most of the radioactive isotope.

There are three types of radiation, alpha, beta and gamma.

Which type of radiation is given out by the radioactive isotope?

Explain your answer.

Use the data in the table to help.