Radioactive emissions: OCR GCSE Physics A questions

Every OCR GCSE Physics A exam question on P6.1 Radioactive emissions, 2018–2025, with its mark scheme and examiner’s report.

All 82 questions on Radioactive emissions, as a list

June 2025, Paper 2 Foundation, Q8 (1 mark): Which material will gamma radiation not easily penetrate? A A sheet of paper B A thick block of lead C A thin sheet of aluminium D Human skin Your answer [1]
June 2025, Paper 2 Foundation, Q18(a) (2 marks): The carbon-14 atom has 6 protons and 8 neutrons in its nucleus. Carbon-12 is a different isotope of carbon. State one similarity and one difference between an a
June 2025, Paper 2 Foundation, Q18(b) (2 marks): An atom of carbon-14 decays by emitting a negatively charged beta particle from the nucleus. Describe the effect this has on the mass number and on the charge o
June 2025, Paper 2 Foundation, Q18(c)(iii) (2 marks): The technicians check the safety of the containers by measuring the count rate next to the container. The count rate is the number of counts of radiation per mi
June 2025, Paper 4 Higher, Q11 (1 mark): Which row describes how a nucleus of an atom changes when a beta particle is emitted? Total number of Number of neutrons Number of protons protons and neutrons
June 2025, Paper 4 Higher, Q20(a)(i) (3 marks): Describe how the technician obtains a precise measurement of the count rate from the radioactive metal. Include the name of any extra equipment the technician u
June 2025, Paper 4 Higher, Q20(a)(ii) (3 marks): Explain how the technician shows that the radioactive metal emits only gamma radiation. Include the name of any extra equipment the technician uses. [3]
June 2025, Paper 4 Higher, Q20(b)(ii) (3 marks): Metal D is considered to be safe when the count rate drops to 1 32 of the original count rate. Calculate the time required for metal D to be safe. Time required
June 2024, Paper 2 Foundation, Q3 (1 mark): One atom of carbon contains 6 protons, 6 electrons and 6 neutrons. Another atom of carbon contains 6 protons, 6 electrons and 7 neutrons. Which answer describes
June 2024, Paper 2 Foundation, Q7 (1 mark): Which diagram shows how alpha particles (α), beta particles (β) and gamma rays (γ) penetrate different materials? A α β γ Paper Aluminium Lead B α β γ Paper Alu
June 2024, Paper 2 Foundation, Q21(a)(i) (1 mark): How can the scientist make the results more accurate? Tick (✓) one box. Handle the radioactive isotope using tongs. Move the radioactive isotope further away fr
June 2024, Paper 2 Foundation, Q21(a)(ii) (1 mark): The activity of a different radioactive isotope is 480 counts per minute (cpm). Calculate the activity in counts per second. Activity = counts per second [1]
June 2024, Paper 2 Foundation, Q23(c)(i) (1 mark): Explain what is meant by the phrase ‘a half-life of 30 years’. [1]
June 2024, Paper 2 Foundation, Q23(c)(ii) (1 mark): Which sentence explains why we use the idea of half-life in radioactive decay? Tick (✓) one box. Radioactive decay is a random process. When a nucleus decays, i
June 2024, Paper 2 Foundation, Q23(c)(iii) (2 marks): In the accident, 28 kg of caesium-137 was released into the atmosphere. What mass of caesium-137 remains undecayed after 90 years? Mass = kg [2]
June 2024, Paper 2 Foundation, Q23(d) (3 marks): A nuclear reactor needs neutrons to start a nuclear fission reaction. A plutonium nucleus (Pu) decays into a uranium nucleus (U) and an alpha particle (4 2He).
June 2024, Paper 4 Higher, Q17(c)(i) (1 mark): Explain what is meant by the phrase ‘a half-life of 30 years’. [1]
June 2024, Paper 4 Higher, Q17(c)(ii) (1 mark): Which sentence explains why we use the idea of half-life in radioactive decay? Tick (✓) one box. Radioactive decay is a random process. When a nucleus decays, i
June 2024, Paper 4 Higher, Q17(c)(iii) (2 marks): In the accident, 28 kg of caesium-137 was released into the atmosphere. What mass of caesium-137 remains undecayed after 90 years? Mass = kg [2]
June 2024, Paper 4 Higher, Q17(d) (3 marks): A nuclear reactor needs neutrons to start a nuclear fission reaction. A plutonium nucleus (Pu) decays into a uranium nucleus (U) and an alpha particle (4 2He).
June 2023, Paper 2 Foundation, Q12 (1 mark): 12 The symbol for an isotope of hydrogen is 1H. What is the correct diagram of the nucleus of this isotope of hydrogen? Key = Neutron = Proton A B C D Your answ
June 2023, Paper 2 Foundation, Q23(c) (2 marks): A 12 mg mass of sodium-24 is added to water. The half-life of sodium-24 is 15 hours. What mass of sodium-24 remains in the water after 30 hours? Mass remaining
June 2023, Paper 4 Higher, Q17(c) (2 marks): A 12 mg mass of sodium-24 is added to water. The half-life of sodium-24 is 15 hours. What mass of sodium-24 remains in the water after 30 hours? Mass remaining
June 2023, Paper 4 Higher, Q18(a)(i) (2 marks): Complete Table 18.1 to show the composition of an alpha particle. Table 18.1 Number of protons Number of neutrons Number of electrons [2]
June 2023, Paper 4 Higher, Q18(a)(ii) (1 mark): A person swallows a small amount of polonium-210. Doctors examine the person using a Geiger-Müller tube outside the body. Explain why the doctors do not detect
June 2023, Paper 4 Higher, Q18(b)(i) (1 mark): In the first step, bismuth-209, 209 83Bi is bombarded with neutrons to make 210 83Bi. State the name given to these different forms of the element bismuth. [1]
June 2023, Paper 4 Higher, Q18(b)(ii) (2 marks): In the second step, 210 83Bi decays to form 210 84Po. Complete the balanced nuclear equation for this decay. 210 210 83Bi 84Po + [2]
June 2023, Paper 4 Higher, Q18(c) (3 marks): 1 μg of polonium-210 is enough to kill a human being. 210 g of polonium-210 has an activity of 3.57 × 1016 Bq. Calculate the activity of a sample of 1 μg of pol
June 2023, Paper 4 Higher, Q18(d)(i) (1 mark): Use the graph to complete Table 18.2. Two answers have been filled in for you. Table 18.2 Time (days) Mass (μg) 0 160 200 30 400 600 [1]
June 2023, Paper 4 Higher, Q18(d)(ii) (2 marks): A teacher explains half-life and radioactive decay to their class. The teacher says, ‘For equal time periods, the ratio: mass at the start of the time period ma
June 2022, Paper 2 Foundation, Q5 (1 mark): The diagram shows a radioactive isotope emitting alpha particles and beta particles. Aluminium Paper (5 mm thick) Radioactive Detector isotope Which particles a
June 2022, Paper 2 Foundation, Q22(a)(i) (1 mark): Complete the symbol for this isotope. P [1]
June 2022, Paper 2 Foundation, Q22(a)(ii) (2 marks): A nucleus of this isotope emits beta radiation. State values for the relative charge and relative mass of the nucleus after beta radiation is emitted. Relative
June 2022, Paper 2 Foundation, Q22(b) (2 marks): The table shows some information for two different isotopes of phosphorous. The isotopes are labelled A and B. Relative charge Relative mass Isotope A +15 29 Is
June 2022, Paper 4 Higher, Q4 (1 mark): A radioactive source has a count-rate of 64 counts per minute (cpm). The half-life of the radioactive source is 10 minutes. What is the count-rate of the radioa
June 2022, Paper 4 Higher, Q17(a)(i) (1 mark): Complete the symbol for this isotope. P [1]
June 2022, Paper 4 Higher, Q17(a)(ii) (2 marks): A nucleus of this isotope emits beta radiation. State values for the relative charge and relative mass of the nucleus after beta radiation is emitted. Relative
June 2022, Paper 4 Higher, Q17(b) (2 marks): The table shows some information for two different isotopes of phosphorous. The isotopes are labelled A and B. Relative charge Relative mass Isotope A +15 29 Is
November 2021, Paper 2 Foundation, Q4 (1 mark): A radioactive source has a count rate of 200 counts per minute (cpm). The half-life of the radioactive source is 3 minutes. What is the count rate of the radioa
November 2021, Paper 2 Foundation, Q7 (1 mark): A radioactive source produces gamma rays. The diagram shows a detector and a piece of lead placed near the radioactive source. Radioactive source Detector Conne
November 2021, Paper 2 Foundation, Q14 (1 mark): Carbon-12 is an isotope of carbon. Carbon-12 contains 6 protons and 6 neutrons. Which atom X is also an isotope of carbon? 11 5 X A 12 5 X B 13 6 X C 13 7 X D Y
November 2021, Paper 2 Foundation, Q19(b)(i) (1 mark): A scientist measures the activity of a sample of Pu-238. The scientist takes five different measurements. Table 19.1 shows their results: Measurement 1 2 3 4 5
November 2021, Paper 2 Foundation, Q19(b)(ii) (2 marks): An alpha particle is emitted by Pu-238. Complete the radioactive decay equation for Pu-238 decay. 238 234 U + 94 Pu 2 He [2]
November 2021, Paper 2 Foundation, Q19(b)(iii) (2 marks): A student says, ‘Alpha radiation is safer than beta.’ Do you agree with this student? Tick (✓) one box. Yes No Explain your answer. [2]
November 2021, Paper 4 Higher, Q1 (1 mark): Carbon-12 is an isotope of carbon. Carbon-12 contains 6 protons and 6 neutrons. Which atom X is also an isotope of carbon? 11 5 X A 12 5 X B 13 6 X C 13 7 X D Y
November 2021, Paper 4 Higher, Q11 (1 mark): A teacher measures the activity of a radioactive source. They place different materials between the radioactive source and detector. The results are shown in th
November 2021, Paper 4 Higher, Q18(b)(i) (1 mark): State why Pu-238 undergoes radioactive decay. [1]
November 2021, Paper 4 Higher, Q18(b)(ii) (2 marks): A Pu-238 nucleus emits an alpha particle. 238 94 Pu Determine the value of the mass of the nucleus and the number of protons after Pu-238 emits an alpha particl
November 2021, Paper 4 Higher, Q18(c) (2 marks): Fig. 18.1 shows how the activity of Pu-238 changes with time. 700 600 500 400 Activity (GBq) 300 200 100 0 0 50 100 150 200 250 300 350 Time (years) Fig. 18.1 U
November 2020, Paper 2 Foundation, Q2 (1 mark): Which statement about alpha particles is correct? A They are fast moving electrons. B They are less penetrating than beta particles. C They can pass through lea
November 2020, Paper 2 Foundation, Q18(a)(i) (1 mark): State the number of protons in a nucleus of Co‑60. Number of protons = [1]
November 2020, Paper 2 Foundation, Q18(a)(ii) (2 marks): Give one similarity and one difference between the nucleus of Co‑57 and the nucleus of Co‑60. Similarity Difference [2]
November 2020, Paper 2 Foundation, Q18(b)(i) (1 mark): Explain why the teacher’s three measurements are not the same. [1]
November 2020, Paper 2 Foundation, Q18(b)(ii) (2 marks): Use the teacher’s results in Table 18.1 to calculate the mean count‑rate for Co‑60. Count‑rate = counts per minute [2]
November 2020, Paper 2 Foundation, Q18(b)(iii) (1 mark): Co‑60 emits gamma radiation. The teacher puts thin aluminium foil between Co‑60 and the detector. State what happens to the count‑rate. [1]
November 2020, Paper 2 Foundation, Q18(c)(i) (1 mark): Explain what is meant by the half‑life of a radioactive isotope. [1]
November 2020, Paper 2 Foundation, Q18(c)(ii) (3 marks): The half‑life of Co‑60 is 5 years. The count‑rate of a sample of Co‑60 is 160 counts per minute. Calculate the count‑rate of the Co‑60 after 10 years. Count‑rat
November 2020, Paper 4 Higher, Q20(a) (2 marks): This is the symbol for americium-241: 241 95 Am Describe the structure of an americium-241 nucleus. [2]
November 2020, Paper 4 Higher, Q20(b) (3 marks): Americium-241 decays by emitting alpha radiation to form neptunium (Np). Complete the balanced symbol equation for the decay. 95Am 241 Np + 2 4 [3]
November 2020, Paper 4 Higher, Q20(d)(i) (1 mark): Explain what is meant by half-life. [1]
June 2019, Paper 2 Foundation, Q12 (1 mark): Which radioactive decay equation is correct? 14 10 4Be + 0 A 6C –1e 14 10 4Be + 0 B 6C 0γ 14 14 7N + 4 C 6C 2He 14 14 7N + 0 D 6C –1e Your answer [1]
June 2019, Paper 2 Foundation, Q22(b) (2 marks): Alpha radiation is not emitted in the processes in part (a). Explain why. [2]
June 2019, Paper 2 Foundation, Q23(a) (1 mark): A radioactive isotope has a half-life of 6 hours. 50 g of the isotope are put in a container. What mass of the isotope is left after 6 hours? Mass = g [1]
June 2019, Paper 2 Foundation, Q23(b)(i) (1 mark): Which isotope, A, B or C, takes the longest time to decay? [1] Tick (✓) one box. A B C
June 2019, Paper 2 Foundation, Q23(b)(iii) (4 marks): Scientist 1 wants to identify the type of radiation emitted by isotope A. This is a list of equipment Scientist 1 has in his laboratory: • radiation detector •
June 2019, Paper 4 Higher, Q8 (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, Paper 4 Higher, Q23(a) (2 marks): Use Fig. 23.1 to calculate the half-life of isotope A. Show your working on the graph in Fig. 23.1. Half-life = minutes [2]
June 2019, Paper 4 Higher, Q23(b) (2 marks): The teacher measures the activity of isotope B. She starts taking activity measurements after 20 minutes. Table 23.1 shows her results for isotope B. Time (minu
June 2019, Paper 4 Higher, Q23(c) (2 marks): The teacher measures the activity of isotope C. Fig. 23.2 is a graph which shows how activity varies with time for isotope C. 2.5 2.0 1.5 Activity (counts per m
June 2018, Paper 2 Foundation, Q13 (1 mark): Which equation shows a correct alpha decay? 24 1 23 9 1Np + 2 A 5Am 4He 9 9 24 1 23 7 3Np + 0 B 5Am 2He 9 9 24 1 23 7 3Np + 4 C 5Am 2He 9 9 24 1 23 7 3Np + 0 D
June 2018, Paper 2 Foundation, Q17(b)(i) (2 marks): Which source A, B, C or D emits gamma radiation only? Explain your answer. Source because [2]
June 2018, Paper 2 Foundation, Q17(b)(ii) (2 marks): Which source A, B, C or D emits alpha radiation only? Explain your answer. Source because [2]
June 2018, Paper 2 Foundation, Q17(b)(iii) (2 marks): Which source A, B, C or D could emit both beta and gamma radiation? Explain your answer. Source because [2]
June 2018, Paper 2 Foundation, Q17(c) (2 marks): The teacher notices that the count rate behind the lead barrier ranges from 20 to 24. Give two reasons why there are a wide range of results around 22 counts pe
June 2018, Paper 2 Foundation, Q17(d) (2 marks): The teacher decides to repeat the experiment. This time he records the number of counts for a much longer time interval for each source. Explain why this is an
June 2018, Paper 4 Higher, Q5 (1 mark): A teacher measures the radiation from a radioactive source for 10 days. 80 70 60 50 Counts per 40 minute 30 20 10 0 0 1 2 3 4 5 6 7 8 9 10 Time (days) What is t
June 2018, Paper 4 Higher, Q6 (1 mark): An alpha particle collides with an atom to produce a positive ion. What happens to the atom for it to become a positive ion? A It loses an electron from inside
June 2018, Paper 4 Higher, Q19(d)(i) (1 mark): Carbon-14 is radioactive and carbon-12 is not radioactive. Explain why some isotopes are radioactive. [1]
June 2018, Paper 4 Higher, Q19(d)(ii) (1 mark): Describe how the nucleus of carbon-12 is different to the nucleus of carbon-14. [1]
June 2018, Paper 4 Higher, Q19(e)(i) (2 marks): Complete the decay equation for alpha emission. ..... 23 0 4 2U 2He + .....Th [2] 9
June 2018, Paper 4 Higher, Q19(e)(ii) (2 marks): Complete the decay equation for beta emission. ..... 21 4 .....β + 21 4 3Bi 4Po [2] 8 8
June 2018, Paper 4 Higher, Q19(e)(iii) (2 marks): Complete the decay equation for gamma emission. ..... 235 0 .....U 0γ + 92U [2]

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