Radioactive decay: past paper questions

Where the questions come from

• Question 38May/June 2026, paper 11Multiple choice1 mark

  Isotope X undergoes radioactive decay to produce nuclei of a different element. Which statement about isotope X must be correct?

  Try this question
• Question 35Oct/Nov 2024, paper 11Multiple choice1 markHas a diagram

  The diagram shows five atoms in a radioactive substance. The atoms each give out an $\alpha$-particle.

  Try this question
• Question 35Oct/Nov 2023, paper 12Multiple choice1 markHas a diagram

  Which row correctly describes an example of radioactive decay?

  Try this question
• Question 39May/June 2026, paper 12Multiple choice1 mark

  Which statement about $\alpha$-particles and $\gamma$-rays is correct?

  Try this question
• Question 37Oct/Nov 2025, paper 22Multiple choice1 mark

  Which change takes place in the nucleus when it decays by beta ($\beta$) emission?

  Try this question
• Question 36Oct/Nov 2024, paper 12Multiple choice1 mark

  Radioactive decay results in the emission of $\alpha$-particles, $\beta$-particles and $\gamma$-radiation. Which types of emission result in a nucleus changing to that of a different element?

  Try this question
• Question 36Oct/Nov 2023, paper 13Multiple choice1 markHas a diagram

  Which type of radioactive decay causes the nucleus of one element to change into the nucleus of another element?

  Try this question
• Question 35Oct/Nov 2025, paper 23Multiple choice1 mark

  Radioactive decay is a change in an unstable nucleus which may result in emission of alpha-particles or beta-particles. Which statement describes how these emissions happen?

  Try this question
• Question 36Oct/Nov 2024, paper 21Multiple choice1 mark

  Which statement about alpha decay is correct?

  Try this question
• Question 37May/June 2026, paper 21Multiple choice1 mark

  The equation shows the decay of radon to form polonium. ${}_{86}^{222}\text{Rn}\to {}_{84}^{218}\text{Po}+\text{X}$ What is X?

  Try this question
• Question 36Oct/Nov 2025, paper 23Multiple choice1 mark

  Which change occurs in the nucleus of a radioactive atom when a beta-particle is emitted?

  Try this question
• Question 34Oct/Nov 2024, paper 23Multiple choice1 mark

  The products of the decay of a nucleus of a radioactive isotope are a nucleus and radiation which is emitted. What is the nature of the products?

  Try this question
• Question 9Oct/Nov 2023, paper 41Structured10 marks

  Many household smoke alarms contain a sample of the radioactive isotope americium-241 (Am). Americium-241 is the isotope of the element americium that has the nucleon number (mass number) 241.

  Try this question
• Question 35May/June 2025, paper 11Multiple choice1 mark

  The unstable nucleus of an element undergoes radioactive decay. The proton number remains unchanged. Which description of this radioactive decay event is correct?

  Try this question
• Question 35Oct/Nov 2024, paper 23Multiple choice1 mark

  An atomic nucleus decays by one or more radioactive decay processes. What causes the proton number to decrease by 1?

  Try this question
• Question 36May/June 2023, paper 11Multiple choice1 mark

  Which statement about the random decay of the nuclei in a sample of uranium-238 is correct?

  Try this question
• Question 10May/June 2026, paper 43Structured7 marks

  Carbon-14 and carbon-11 are different isotopes of carbon used in medicine. State the similarity and the difference between the composition of the nuclei of carbon-14 and carbon-11.

  Try this question
• Question 36May/June 2025, paper 21Multiple choice1 mark

  Sodium-24 is a radioactive isotope that emits beta radiation. Which nuclear equation shows how sodium-24 decays?

  Try this question
• Question 37Oct/Nov 2024, paper 23Multiple choice1 markHas a diagram

  The diagram shows a system to control the thickness of paper produced by a machine. The graph shows how the count rate at the detector varies with the thickness of the paper.

  Try this question
• Question 35May/June 2023, paper 22Multiple choice1 mark

  Which change occurs in the nucleus of a radioactive atom during $\beta$-emission?

  Try this question
• Question 36May/June 2025, paper 23Multiple choice1 mark

  Isotope X is radioactive. Which statement about X must be correct?

  Try this question
• Question 8Oct/Nov 2024, paper 41Structured10 marksHas a diagram

  The nuclide notation for the radioactive isotope carbon-14 is ${}_6^{14}\mathrm{C}$. Using the symbols shown in Fig. 8.1, draw a diagram to show the number of electrons, neutrons and protons in a neutral atom of carbon-14 and how they are arranged.

  Try this question
• Question 35May/June 2023, paper 23Multiple choice1 mark

  Which change is occurring in a nucleus during $\beta$-emission?

  Try this question
• Question 9May/June 2025, paper 41Structured10 marksHas a diagram

  Strontium-90 (${}_{38}^{90}\text{Sr}$) is a radioactive isotope that contains 38 protons and 52 neutrons. Strontium-90 decays to form an isotope of yttrium ($\text{Y}$) by emitting beta ($\beta$) particles.

  Try this question
• Question 34May/June 2024, paper 11Multiple choice1 mark

  An isotope of radon is radioactive. It decays by emitting an $\alpha$-particle. What happens to the nucleus of a radon atom during the emission of the $\alpha$-particle?

  Try this question
• Question 9May/June 2023, paper 41Structured8 marksHas a diagram

  Fig. 9.1 represents all the particles in a neutral atom of a radioactive isotope X1. Fig. 9.1 (not to scale) Determine the number of neutrons in this atom and explain how the answer is obtained.

  Try this question
• Question 9May/June 2025, paper 42Structured7 marks

  State what is meant by background radiation.

  Try this question
• Question 34May/June 2024, paper 13Multiple choice1 markHas a diagram

  A radiation detector in a laboratory is measuring background radiation. Which row describes the readings and the cause?

  Try this question
• Question 9May/June 2023, paper 42Structured10 marks

  Table 9.1 shows some properties and values for $\alpha$-particles, $\beta$-particles and $\gamma$-radiation. Complete Table 9.1.

  Try this question
• Question 11May/June 2025, paper 43Structured7 marks

  Define the half-life of a radioactive source.

  Try this question