plumiWhat is radioactivity?: OCR GCSE Combined Science B questions
Every OCR GCSE Combined Science B exam question on P5.1 What is radioactivity?, 2018–2025, with its mark scheme and examiner’s report.
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Q2(a)
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Q2(b)(i)
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Q7(b)
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Q5(a)(ii)
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Q9(a)
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Q9(b)
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Q2(a)
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Q2(b)
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Q5(a)
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All 73 questions on What is radioactivity?, as a list
- June 2025, Physics Paper 3 Foundation, Q2(a) (3 marks): Complete the sentences to describe the parts of an atom. Put a ring around each correct option. The nucleus of the atom has a negative / neutral / positive char
- June 2025, Physics Paper 3 Foundation, Q2(b)(i) (1 mark): Which nucleus has the largest charge? [1]
- June 2025, Physics Paper 3 Foundation, Q2(b)(ii) (1 mark): Which two nuclei are isotopes of the same element? and [1]
- June 2025, Combined Science Paper 4 Foundation, Q7(a) (2 marks): Use the graph to find the half-life of carbon-15. Half-life = s [2]
- June 2025, Combined Science Paper 4 Foundation, Q7(b) (6 marks): Carbon-15 is a radioactive isotope that emits beta particles. The graph shows the activity of a sample of carbon-15. 400 380 360 340 320 300 280 260 240 220 Act
- June 2025, Physics Paper 7 Higher, Q5(a)(i) (2 marks): Complete the table to describe the nucleus of americium-241. Number of neutrons Number of protons [2]
- June 2025, Physics Paper 7 Higher, Q5(a)(ii) (2 marks): There are many different isotopes of americium. Describe what is meant by the term isotope. [2]
- June 2025, Physics Paper 7 Higher, Q5(a)(iii) (2 marks): Americium-241 is radioactive and decays into an isotope of neptunium by emitting radiation X. This is represented by the equation: 24 1 23 7 5 Am 3 Np + X 9 9 I
- June 2025, Physics Paper 7 Higher, Q5(b) (2 marks): Americium-241 is used in household smoke detectors. It has a half-life of 430 years. Explain why this half-life makes americium-241 suitable for use in smoke de
- June 2024, Combined Science Paper 4 Foundation, Q8(c) (2 marks): One of the samples in the table is radium-226. Determine the number of neutrons in a nucleus of a radium-226 atom. Use the Data and Equation Sheet. Number of ne
- June 2024, Combined Science Paper 4 Foundation, Q9(a) (1 mark): What is the definition for the activity of a radioactive source? Tick (✓) one box. The current produced by the particles. The purpose the radioactive sample is
- June 2024, Combined Science Paper 4 Foundation, Q9(b) (1 mark): What is the definition of half-life? Tick (✓) one box. Half of the original activity of a sample. Half the lifetime of a radioactive substance. The time for hal
- June 2024, Combined Science Paper 4 Foundation, Q9(c) (3 marks): The graph shows experimental data from a radiation detector, and a separate mathematical model of decay. 900 800 700 Mathematical model Mathematical model Mathe
- June 2024, Combined Science Paper 8 Higher, Q1(c) (2 marks): One of the samples in the table is radium-226. Determine the number of neutrons in a nucleus of a radium-226 atom. Use the Data and Equation Sheet. Number of ne
- June 2024, Combined Science Paper 8 Higher, Q2(a) (1 mark): What is the definition for the activity of a radioactive source? Tick (✓) one box. The current produced by the particles. The purpose the radioactive sample is
- June 2024, Combined Science Paper 8 Higher, Q2(b) (1 mark): What is the definition of half-life? Tick (✓) one box. Half of the original activity of a sample. Half the lifetime of a radioactive substance. The time for hal
- June 2024, Combined Science Paper 8 Higher, Q2(c) (3 marks): The graph shows experimental data from a radiation detector, and a separate mathematical model of decay. 900 800 700 Mathematical model Mathematical model Mathe
- June 2023, Physics Paper 3 Foundation, Q2(a) (1 mark): This radioactive decay graph shows how the percentage of technetium-99m remaining in the tracer changes with time. 100 Percentage of technetium-99m 90 remaining
- June 2023, Physics Paper 7 Higher, Q5(a) (2 marks): Complete the label, using data from the table. I [2]
- June 2023, Physics Paper 7 Higher, Q5(c)(i) (1 mark): Gamma rays can be emitted when radioactive nuclei decay. State two other possible emissions from radioactive nuclei when they decay. 1 2 [1]
- June 2023, Physics Paper 7 Higher, Q5(c)(ii) (1 mark): Why do radioactive nuclei decay? [1]
- June 2023, Physics Paper 7 Higher, Q5(c)(iii) (1 mark): Complete the sentences to describe what can change when the nucleus of an atom decays radioactively. Put a ring around each correct option. The charge of the nu
- June 2023, Physics Paper 7 Higher, Q5(d) (2 marks): In 2010 a new element was discovered. In 2015 the element was recognised officially. It is called tennessine. Between 2010 and 2015 publications about tennessin
- June 2022, Physics Paper 3 Foundation, Q4(a) (2 marks): Complete the sentences to describe the nucleus of an atom. Put a ring around each correct option. All atoms have a positively charged nucleus because the nucleu
- June 2022, Physics Paper 3 Foundation, Q4(b) (4 marks): The scientific model of the atom has changed over time. Draw lines, to connect the scientist to the description of the model they developed and the order in whi
- June 2022, Physics Paper 3 Foundation, Q4(c) (2 marks): Describe how Bohr’s model of the atom is different to Rutherford’s model of the atom. [2]
- June 2022, Physics Paper 3 Foundation, Q4(d) (3 marks): Which statements about atoms and electromagnetic radiation are true and which are false? Tick (3) one box in each row. True False Infrared radiation is emitted
- June 2022, Physics Paper 3 Foundation, Q9(a) (1 mark): When paper is placed between the radioactive source and the radiation detector the count rate is higher than when no material is used. Some students try to expl
- June 2022, Physics Paper 3 Foundation, Q9(b) (3 marks): The table shows if the materials absorb alpha, beta or gamma radiation. Radiation absorbed Absorbing material Alpha Beta Gamma Paper 3 Thin aluminium 3 3 Thick
- June 2022, Physics Paper 3 Foundation, Q9(c) (1 mark): Carbon-14 is a radioactive source that can be used to find the age of some objects. Fig. 9.3 shows the percentage of carbon-14 remaining in a sample, over time.
- June 2022, Physics Paper 7 Higher, Q9(a) (2 marks): What are isotopes of an element? [2]
- June 2022, Physics Paper 7 Higher, Q9(b) (2 marks): Uranium-234 decays by emitting an alpha particle. Complete the following equation for the decay of uranium-234 to thorium. 23 4 2U Th + 9 [2]
- June 2022, Physics Paper 7 Higher, Q9(c) (3 marks): The graph shows the decay of a sample of uranium-234. Count rate (counts / s) 7000 6000 5000 4000 3000 2000 1000 0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 Time (× 105 y
- June 2022, Physics Paper 7 Higher, Q9(d)(i) (1 mark): After about ten uranium-234 half-lives have passed, this method of finding the age can no longer be used. Suggest one reason why this method no longer works. Us
- June 2022, Physics Paper 7 Higher, Q9(d)(ii) (3 marks): By measuring the amount of thorium in a sample, Ling calculates that 75% of the uranium-234 in the sample has decayed. Calculate the age of the sample. Use the
- June 2022, Combined Science Paper 8 Higher, Q9(a) (3 marks): Complete the nuclear equation for the decay of the uranium isotope into an isotope of thorium (Th). 234 ….....… 92U Th + ….....… ….....… [3]
- June 2022, Combined Science Paper 8 Higher, Q9(b)(i) (3 marks): A woolly mammoth was discovered in a melting glacier. 14 The net decline of 6C emission of the mammoth was recorded as 1/4. Calculate how long ago the woolly ma
- June 2022, Combined Science Paper 8 Higher, Q9(b)(ii) (1 mark): Suggest one reason why the value calculated in (b)(i) is likely to be inaccurate. [1]
- November 2021, Physics Paper 3 Foundation, Q8(a) (2 marks): Draw lines to connect each description with the correct particle. Description Particle electrons Isotopes of an element have the same number of neutrons Isotope
- November 2021, Physics Paper 3 Foundation, Q8(b)(i) (1 mark): If half-life was the only factor affecting how hazardous the isotope was, which isotope would be the most hazardous? Put a ring around the correct answer. Caesi
- November 2021, Physics Paper 3 Foundation, Q8(b)(ii) (2 marks): Explain why your answer to (b)(i) is the most hazardous isotope. [2]
- November 2021, Physics Paper 7 Higher, Q3(c)(iii) (2 marks): What fraction of the radioactive tracer remains radioactive 1 day after being injected into a person’s blood? Tracer half-life = 6 hours Fraction = [2]
- November 2020, Physics Paper 3 Foundation, Q5(a)(i) (1 mark): Carbon has 6 protons. What is the symbol for the isotope carbon-14? Put a ring around the correct answer. 6 6 8 14 8C 14C 6C 6C [1]
- November 2020, Physics Paper 3 Foundation, Q5(a)(ii) (1 mark): The most common isotope of carbon is carbon-12. Define the term isotope. [1]
- November 2020, Physics Paper 3 Foundation, Q5(b) (2 marks): Uranium-238 is an isotope and decays into thorium-234 by emitting an alpha particle. This process is called alpha decay. 238 234 90Th + 4 92U 2He How does the n
- November 2020, Physics Paper 7 Higher, Q8(a)(i) (3 marks): Calculate the fraction of the radioactive emission from Caesium-137 that will still be present in 2076. Fraction = [3]
- November 2020, Physics Paper 7 Higher, Q8(a)(ii) (3 marks): What year will the fraction have fallen to 64 of the original radioactive emission? Year = [3]
- June 2019, Physics Paper 3 Foundation, Q7(a) (1 mark): Why are some nuclei radioactive? [1]
- June 2019, Physics Paper 3 Foundation, Q7(c)(i) (2 marks): Uranium-234 Thorium-230 234 92U → 230 90Th He [2]
- June 2019, Physics Paper 3 Foundation, Q7(c)(ii) (2 marks): Strontium-90 Yttrium-90 90 → 90 38Sr 39Y + e [2]
- June 2019, Physics Paper 7 Higher, Q6(a)(i) (2 marks): Americium-241 and promethium-147 are radioactive isotopes used in industrial processes. Complete the decay equations for these isotopes.
- June 2019, Physics Paper 7 Higher, Q6(a)(ii) (3 marks): 147 61Pm → Sm + e [3]
- June 2018, Physics Paper 3 Foundation, Q7(a) (2 marks): Explain what the half-life of a radioactive isotope means. [2]
- June 2018, Physics Paper 3 Foundation, Q7(b) (2 marks): This graph shows how the activity of a cerium-131 source changes over time. 150 100 activity (counts per minute) 50 0 0 10 20 30 40 time (minutes) Use the graph
- June 2018, Physics Paper 3 Foundation, Q9(a) (5 marks): Describe the structure of the atom. Include information about particles that make up the atom. You may include a diagram. [5]
- June 2018, Physics Paper 3 Foundation, Q9(b)(i) (1 mark): What is the size of a typical atom? Draw a ring around the correct answer. 10–15 m 10–10 m 10–5 m 10–1 m 105 m 1010 m [1]
- June 2018, Physics Paper 3 Foundation, Q9(b)(ii) (1 mark): How does the size of the nucleus compare to the size of an atom? [1]
- June 2018, Physics Paper 3 Foundation, Q9(c)(i) (1 mark): What did J.J. Thomson discover, that appeared to come from the atom? [1]
- June 2018, Physics Paper 3 Foundation, Q9(c)(ii) (3 marks): The model changed because of J.J. Thomson’s discovery. Describe the new model J.J. Thomson suggested. [3]
- June 2018, Physics Paper 3 Foundation, Q9(d) (2 marks): The element carbon has two isotopes, carbon-12 and carbon-14. What is the difference between these two isotopes? [2]
- June 2018, Physics Paper 7 Higher, Q1(a) (5 marks): Describe the structure of the atom. Include information about particles that make up the atom. You may include a diagram. [5]
- June 2018, Physics Paper 7 Higher, Q1(b)(i) (1 mark): What is the size of a typical atom? Draw a ring around the correct answer. 10–15 m 10–10 m 10–5 m 10–1 m 105 m 1010 m [1]
- June 2018, Physics Paper 7 Higher, Q1(b)(ii) (1 mark): How does the size of the nucleus compare to the size of an atom? [1]
- June 2018, Physics Paper 7 Higher, Q1(c)(i) (1 mark): What did J.J. Thomson discover, that appeared to come from the atom? [1]
- June 2018, Physics Paper 7 Higher, Q1(c)(ii) (3 marks): The model changed because of J.J. Thomson’s discovery. Describe the new model J.J. Thomson suggested. [3]
- June 2018, Physics Paper 7 Higher, Q1(d) (2 marks): The element carbon has two isotopes, carbon-12 and carbon-14. What is the difference between these two isotopes? [2]
- June 2018, Physics Paper 7 Higher, Q9(a) (2 marks): Use the graph to find the half-life of cobalt-60. Show your working on the graph. Half-life = years [2]
- June 2018, Physics Paper 7 Higher, Q9(b) (4 marks): One of the sources from the rack of cobalt-60 has an activity of 1.2 × 1013 counts per second. The source must be replaced when the activity falls to 7.5 × 1011
- June 2018, Combined Science Paper 8 Higher, Q5(a)(i) (3 marks): Carbon-14 decays by emitting a β-particle and forming an isotope of nitrogen. Complete the equation for the decay of carbon-14. 14 6 C → N + β [3]
- June 2018, Combined Science Paper 8 Higher, Q5(a)(ii) (2 marks): The graph shows the decay curve for carbon-14. 100 90 80 70 60 50 40 30 20 10 0 0 5 10 15 20 25 30 35 40 time (thousand years) Use the graph to find the half-li
- June 2018, Combined Science Paper 8 Higher, Q5(b)(i) (1 mark): Suggest one assumption that must be made when dating samples using carbon-14. [1]
- June 2018, Combined Science Paper 8 Higher, Q5(b)(ii) (5 marks): When potassium-40 decays, one decay product is argon-40. Argon-40 makes up 99.6% of the argon on earth. The half-life of potassium-40 is 1.251 × 109 years. Expl
- June 2018, Combined Science Paper 8 Higher, Q5(c) (1 mark): Some stable isotopes are used to investigate archaeological objects. In 2012, the skeleton of King Richard III was discovered under a car park in Leicester. Sci
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