Radioactivity: OCR GCSE Combined Science A questions

Every OCR GCSE Combined Science A exam question on P4.3 Radioactivity, 2018–2025, with its mark scheme and examiner’s report.

All 104 questions on Radioactivity, as a list

June 2025, Physics Paper 6 Foundation, Q6 (1 mark): Which statement about electrons in atoms is correct? A Electrons gain energy as they absorb electromagnetic waves. B Electrons have a positive charge. C Electro
June 2025, Physics Paper 6 Foundation, Q13(a) (1 mark): The isotope carbon-12 has the symbol 12 6C. What is the relative charge on a carbon-12 nucleus? Tick (✓) one box. – 6 +6 +12 [1]
June 2025, Physics Paper 6 Foundation, Q13(b) (2 marks): Another isotope of carbon is carbon-14. Carbon-14 has the symbol 14 6C Complete the sentences to compare a nucleus of carbon-12 and a nucleus of carbon-14. Put
June 2025, Physics Paper 6 Foundation, Q13(c) (2 marks): When carbon-14 decays into nitrogen-14, it emits beta radiation. Complete the equation for the decay of carbon-14. 14 6C 14N + –1β ..... ..... [2]
June 2025, Physics Paper 6 Foundation, Q13(d) (1 mark): Carbon-14 has a half-life of 5700 years. Explain what half-life means. [1]
June 2025, Physics Paper 6 Foundation, Q13(e) (2 marks): 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
June 2025, Physics Paper 12 Higher, Q4 (1 mark): A geologist places different materials between a rock and a radiation detector to determine if the rock emits beta particles. Rock Material Radiation detector a
June 2025, Physics Paper 12 Higher, Q15(a)(i) (1 mark): Which particles inside the atom absorb ultraviolet radiation and emit visible light? [1]
June 2025, Physics Paper 12 Higher, Q15(a)(ii) (1 mark): Describe what happens to these particles when they absorb ultraviolet radiation. [1]
June 2025, Physics Paper 12 Higher, Q15(a)(iii) (2 marks): Electromagnetic waves with short wavelengths can cause ionisation when absorbed by these particles inside the atom. Describe the effect ionisation has on the at
June 2025, Physics Paper 12 Higher, Q16(a) (2 marks): Describe one similarity and one difference between a nucleus of iodine-127 and a nucleus of iodine-131. Similarity Difference [2]
June 2025, Physics Paper 12 Higher, Q16(b)(i) (1 mark): Use the graph to show that the half-life of iodine-131 is approximately 8 days. Show your working on the graph. [1]
June 2025, Physics Paper 12 Higher, Q16(b)(ii) (2 marks): 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 h
June 2025, Physics Paper 12 Higher, Q16(b)(iii) (2 marks): 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 rad
June 2024, Physics Paper 6 Foundation, Q8 (1 mark): An atom absorbs electromagnetic radiation. What happens to some electrons in this atom? A They form a neutron. B They form a new element. C They move from a hig
June 2024, Physics Paper 6 Foundation, Q10 (1 mark): Some students design a practical to model radioactive decay. Which model is correct? A Throw a coin in the air 100 times and count the number of heads or tails.
June 2024, Physics Paper 6 Foundation, Q11(a) (3 marks): Some atoms and isotopes of elements are shown. 7N 14 15 7 3 7N 3Li 1H Which statements are correct for these atoms and isotopes? Tick (3) three boxes. 7 3Li and
June 2024, Physics Paper 6 Foundation, Q11(b) (1 mark): A nuclear scientist investigates the radiation emitted when a nucleus of uranium‑238 decays. The diagram shows the experiment. Radiation Nucleus of uranium-238
June 2024, Physics Paper 6 Foundation, Q11(c) (2 marks): 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 qu
June 2024, Physics Paper 6 Foundation, Q11(d) (1 mark): Why do some atoms emit nuclear radiation? [1]
June 2024, Physics Paper 6 Foundation, Q11(e) (2 marks): 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. Half‑life = days
June 2024, Physics Paper 12 Higher, Q2 (1 mark): Some students design a practical to model radioactive decay. Which model is correct? A Throw a coin in the air 100 times and count the number of heads or tails.
June 2024, Physics Paper 12 Higher, Q14(a) (2 marks): Circle two points on the graph which are isotopes of the same element. Explain how you worked out your answer. [2]
June 2024, Physics Paper 12 Higher, Q14(b)(i) (2 marks): 234Pa. Atomic number Mass [2]
June 2024, Physics Paper 12 Higher, Q14(b)(ii) (1 mark): Which type of radiation is emitted when 234Th decays into 234Pa? [1]
June 2024, Physics Paper 12 Higher, Q14(c) (2 marks): Complete the balanced nuclear decay equation for the decay of 222Rn into 218Po. 222 218 Rn Po + He [2]
June 2024, Physics Paper 12 Higher, Q14(d) (1 mark): Eventually the isotope 206Pb is formed and the decay chain stops. Explain why the decay chain stops at 206Pb. [1]
June 2024, Physics Paper 12 Higher, Q14(e) (3 marks): The half‑life of 238U is 4.5 × 109 years. Determine the ratio of 238U : 234Th after 1.8 × 1010 years. Ratio of 238U : 234Th = : [3]
June 2023, Physics Paper 6 Foundation, Q8 (1 mark): When an alpha particle hits a beryllium nucleus, a particle ‘X’ is emitted. What is the missing number, labelled n in the equation? 4 2He + 9 12 6C + 1 4Be nX A
June 2023, Physics Paper 6 Foundation, Q13 (6 marks): 13* Alpha, beta and gamma radiation have different penetrating powers. A teacher investigates whether a radioactive source is emitting alpha, beta or gamma radi
June 2023, Physics Paper 6 Foundation, Q16(a) (1 mark): Fig. 16.1 shows the scientist walking very close to the radioactive material. Fig. 16.1 Radioactive material Describe the effect of the radioactive material on
June 2023, Physics Paper 6 Foundation, Q16(b) (1 mark): 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
June 2023, Physics Paper 6 Foundation, Q16(c) (1 mark): 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 Descri
June 2023, Physics Paper 12 Higher, Q4 (1 mark): This is the nuclear equation for an alpha particle hitting a beryllium nucleus. 4 2He + 9 12 4Be 6C + X What is X? 1 A 0n 0 B 1e – 4 C 2He 0 D 0γ Your answer [1
June 2023, Physics Paper 12 Higher, Q11(a) (1 mark): Fig. 11.1 shows the scientist walking very close to the radioactive material. Fig. 11.1 Radioactive material Describe the effect of the radioactive material on
June 2023, Physics Paper 12 Higher, Q11(b) (1 mark): 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
June 2023, Physics Paper 12 Higher, Q11(c) (1 mark): 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 Descri
June 2023, Physics Paper 12 Higher, Q16 (6 marks): 16* The graph shows how the activity of a radioactive isotope changes with time. The graph can be used to determine the half-life of the isotope. 100 80 60 Acti
June 2022, Physics Paper 6 Foundation, Q4 (1 mark): Some radioactive elements give out beta radiation. What is beta radiation stopped by? A Aluminium B Thin cardboard C Thin paper D Skin Your answer [1]
June 2022, Physics Paper 6 Foundation, Q11(a) (2 marks): Uranium-238 is a radioactive isotope. When uranium decays, it gives out an alpha particle forming thorium-234. Complete the radioactive decay equation using the
June 2022, Physics Paper 6 Foundation, Q11(b) (2 marks): Atoms can give out different types of electromagnetic radiation. Draw lines to connect each question with its correct answer. Question Answer Radiation with a l
June 2022, Physics Paper 6 Foundation, Q18(a) (2 marks): Which statements about the nucleus of an atom are correct? Tick (✓) two boxes. In radioactive atoms, the nucleus is stable. Most of the nucleus contains empty s
June 2022, Physics Paper 6 Foundation, Q18(b) (2 marks): The graph shows how the mass of a radioactive element changes with time. Mass Time Describe the trend shown by the graph. [2]
June 2022, Physics Paper 12 Higher, Q7 (1 mark): The diagram shows an electron in an atom. Energy level Electron Nucleus When the electron moves between energy levels, the atom emits electromagnetic radiation.
June 2022, Physics Paper 12 Higher, Q8 (1 mark): The table shows information about the number of protons, neutrons and electrons in different atoms. Atom Number of protons Number of neutrons Number of electron
June 2022, Physics Paper 12 Higher, Q12(a) (2 marks): Which statements about the nucleus of an atom are correct? Tick (✓) two boxes. In radioactive atoms, the nucleus is stable. Most of the nucleus contains empty s
June 2022, Physics Paper 12 Higher, Q12(b) (2 marks): The graph shows how the mass of a radioactive element changes with time. Mass Time Describe the trend shown by the graph. [2]
June 2022, Physics Paper 12 Higher, Q15(a) (2 marks): An old unit of activity is the Curie (Ci). • The activity of Cs-137 released in the explosion was 2 300 000 Ci. • 1 Ci = 37 000 000 000 Bq Calculate the activit
June 2022, Physics Paper 12 Higher, Q15(b) (3 marks): Cs-137 emits beta radiation. The table shows some information about this decay. Element Symbol Charge on nucleus Mass of nucleus Caesium Cs +55 137 Barium Ba +5
June 2022, Physics Paper 12 Higher, Q15(c) (6 marks): The isotopes I-131 and Cs-137 from Chernobyl contaminated sheep. The government stopped the movement of contaminated sheep for 26 years. • If the activity per k
November 2021, Physics Paper 6 Foundation, Q7 (1 mark): P, Q, R and S are isotopes. 4 2P 6 3Q 3 2R 2 1S Which two atoms are isotopes of the same element? 4 and 3 2P 2R A 6 and 3 3Q 2R B 3 and 2 1S 2R C 4 and 2 2P 1S
November 2021, Physics Paper 6 Foundation, Q11(b)(i) (1 mark): The charge on the nucleus of isotope X stays the same. What happens to the mass number of the nucleus? [1]
November 2021, Physics Paper 6 Foundation, Q11(b)(ii) (1 mark): Isotope X is stored safely in a container. Suggest a material for the container. [1]
November 2021, Physics Paper 6 Foundation, Q11(c) (2 marks): Describe how an object can be irradiated using isotope X. [2]
November 2021, Physics Paper 6 Foundation, Q11(d)(i) (1 mark): Which box is best for storing isotope Y? Give one reason for your answer using the information in Table 11.1. [1]
November 2021, Physics Paper 6 Foundation, Q11(d)(ii) (1 mark): 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? [1]
November 2021, Physics Paper 6 Foundation, Q11(e)(i) (1 mark): Complete Table 11.2 using the graph to help you. Time (days) Quantity of isotope Y (%) 5 10 Table 11.2 [1]
November 2021, Physics Paper 6 Foundation, Q11(e)(ii) (1 mark): Explain why the half-life of isotope Y is 5 days. [1]
November 2021, Physics Paper 12 Higher, Q4 (1 mark): An atom of element X can be written like this: 2 0 1 X 1 What does an atom of element X contain? A 11 protons, 9 neutrons and 11 electrons B 11 protons, 11 neut
November 2021, Physics Paper 12 Higher, Q9 (1 mark): This is a model of energy levels inside a hydrogen atom. The arrows shown as and represent an electron moving between energy levels. Energy level of an electron
November 2021, Physics Paper 12 Higher, Q14(a) (2 marks): Complete Table 14.1 to show what happens to a nucleus of an atom when an alpha particle or a beta particle is emitted. Alpha particle emitted Beta particle emit
November 2021, Physics Paper 12 Higher, Q14(b) (1 mark): 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? [1]
November 2021, Physics Paper 12 Higher, Q14(c) (2 marks): 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. Half-life = days [2]
November 2021, Physics Paper 12 Higher, Q14(d) (2 marks): 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 cou
November 2021, Physics Paper 12 Higher, Q14(e) (2 marks): The scientist accidentally places isotope X close to isotope Y. Explain why isotope Y is irradiated, but not contaminated, by isotope X. [2]
November 2020, Physics Paper 6 Foundation, Q12(a)(i) (1 mark): What is the mean activity of the isotope? Mean activity = Bq [1]
November 2020, Physics Paper 6 Foundation, Q12(a)(ii) (2 marks): Is there a pattern in the results in Table 12.1? Explain your answer using ideas about radioactivity. [2]
November 2020, Physics Paper 6 Foundation, Q12(b)(i) (1 mark): Carbon-12 is a stable isotope. Carbon-14 is an unstable radioactive isotope. Table 12.2 shows the contents of each nucleus. Carbon-12 Carbon-14 Number of proton
November 2020, Physics Paper 6 Foundation, Q12(b)(ii) (1 mark): This is the equation for the radioactive decay of carbon-14: 14 14 7N + 0 6C -1e What happens to the nuclear mass (mass number) when carbon-14 decays? [1]
November 2020, Physics Paper 6 Foundation, Q12(c)(i) (1 mark): What is meant by the half-life of an isotope? [1]
November 2020, Physics Paper 6 Foundation, Q12(c)(ii) (1 mark): Use the data in Table 12.3 to calculate the half-life of americium-241. Half-life = years [1]
November 2020, Physics Paper 6 Foundation, Q12(c)(iii) (3 marks): This is a diagram of a smoke alarm. Americium-241 Smoke Radiation detector Smoke enters the smoke alarm, which blocks the radiation emitted by the americium-241
November 2020, Physics Paper 12 Higher, Q6 (1 mark): 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 conn
November 2020, Physics Paper 12 Higher, Q12(a) (1 mark): Describe what is meant by the term isotope. [1]
November 2020, Physics Paper 12 Higher, Q12(b)(i) (1 mark): Which type of radiation is emitted by carbon-14? [1]
November 2020, Physics Paper 12 Higher, Q12(b)(ii) (2 marks): Describe how the mass and charge of the nucleus changes when the carbon-14 decays. Mass Charge [2]
November 2020, Physics Paper 12 Higher, Q12(c) (2 marks): This is a diagram of energy levels inside a hydrogen atom. Increasing energy Electron Electromagnetic radiation can cause ionisation. Explain what is meant by t
November 2020, Physics Paper 12 Higher, Q12(d) (3 marks): 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
June 2019, Physics Paper 6 Foundation, Q4 (1 mark): Which statement is correct? A Changes in atoms and nuclei can generate radiations over a wide range of frequencies. B Changes in atoms and nuclei can generate r
June 2019, Physics Paper 6 Foundation, Q13(a) (1 mark): Why are some atoms radioactive? [1]
June 2019, Physics Paper 6 Foundation, Q13(b)(i) (2 marks): Complete the equation for the beta decay. 32 32 15P S + –1β [2]
June 2019, Physics Paper 6 Foundation, Q13(b)(ii) (4 marks): 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 you
June 2019, Physics Paper 6 Foundation, Q13(c) (1 mark): Beta particles are one type of radioactive particle. Name a different particle given out by radioactive atoms. [1]
June 2019, Physics Paper 6 Foundation, Q16(a) (3 marks): Describe the difference between mean, mode and median. In your answer use data from the second throw in the table (shaded in grey). [3]
June 2019, Physics Paper 6 Foundation, Q16(b) (1 mark): Use the table to estimate the half-life of the dice. Give your answer to the nearest whole number. Half-life = throws [1]
June 2019, Physics Paper 12 Higher, Q1 (1 mark): Radioactive elements can contaminate or irradiate objects. Which statement describes irradiation? A Radiation from outside your body travels into your body. B R
June 2019, Physics Paper 12 Higher, Q6 (1 mark): Which statement is true for isotopes of the same element? Np = number of protons and Nn = number of neutrons. A Np = Nn B Np is the same but Nn is different C N
June 2019, Physics Paper 12 Higher, Q9 (1 mark): Beryllium-13 (13 9 4Be) is a radioactive isotope. This is the equation for the decay of beryllium-13. 13 12 4Be 4Be + X What is X? A An alpha particle B A beta
June 2019, Physics Paper 12 Higher, Q12(a) (3 marks): Describe the difference between mean, mode and median. In your answer use data from the second throw in the table (shaded in grey). [3]
June 2019, Physics Paper 12 Higher, Q12(b) (1 mark): Use the table to estimate the half-life of the dice. Give your answer to the nearest whole number. Half-life = throws [1]
June 2019, Physics Paper 12 Higher, Q13(a) (4 marks): 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
June 2019, Physics Paper 12 Higher, Q13(b)(i) (1 mark): Describe how these atoms can emit radiation. [1]
June 2019, Physics Paper 12 Higher, Q13(b)(ii) (1 mark): What type of radiation is emitted? [1]
June 2018, Physics Paper 6 Foundation, Q3 (1 mark): Atoms contain electrons. An atom can lose its outer electrons. What is this process called? A Friction B Ionisation C Radiation D Radioactive decay Your answer
June 2018, Physics Paper 6 Foundation, Q7 (1 mark): An element gives out a beta (β) particle. The table shows how the atomic number and mass number of the element change. Atomic number Mass number A Decreases by
June 2018, Physics Paper 6 Foundation, Q11(a) (2 marks): Two isotopes of nitrogen are shown below. 14 15 7N 7N Explain what is meant by the term isotopes. [2]
June 2018, Physics Paper 6 Foundation, Q11(b)(i) (1 mark): Suggest why the teacher places lead around most of the radioactive isotope. [1]
June 2018, Physics Paper 6 Foundation, Q11(b)(ii) (3 marks): 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
June 2018, Physics Paper 12 Higher, Q2 (1 mark): This is a model of energy levels inside an atom. Increasing A energy B C D The arrows shown as and are electrons moving between energy levels. Which electron mo
June 2018, Physics Paper 12 Higher, Q14(a)(i) (2 marks): Explain what is meant by the term half-life. [2]
June 2018, Physics Paper 12 Higher, Q14(a)(ii) (1 mark): The graph shows how activity of isotope Q and isotope R change with time. Activity Q R Time Which isotope, Q or R, has the longest half-life? Explain your answe
June 2018, Physics Paper 12 Higher, Q14(b) (3 marks): The table shows information about different elements. Element Symbol Atomic number Antimony Sb 51 Caesium Cs 55 Iodine 53 I Tellurium Te 52 Xenon Xe 54 Iodine-1
June 2018, Physics Paper 12 Higher, Q14(c)(i) (1 mark): Use the table to calculate the ratio: activity after 4 days activity after 20 days Answer = [1]
June 2018, Physics Paper 12 Higher, Q14(c)(ii) (2 marks): Use your answer to (c)(i) to calculate the half-life of iodine-131. Answer = days [2]

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