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Radioactivity · CAPE Physics Unit 2

193 past-paper questions on Radioactivity, part of Atomic and Nuclear Physics, from every CAPE Physics Unit 2 paper on Quelpr.

Practise Radioactivity
  1. 9(a)3 marks· CAPE Physics Unit 2 · 2001 · Paper 1For radioactive decay A = λN, complete the table giving the name of EACH term and the corresponding S.I. unit.
  2. 9(b)(i)1 mark· CAPE Physics Unit 2 · 2001 · Paper 1State the physical condition which ensures a good though not exact obedience to the radioactive decay law N = N₀ exp(-λt).
  3. 9(b)(ii)1 mark· CAPE Physics Unit 2 · 2001 · Paper 1Calculate the number of atoms in 1 g of ²²⁶₈₈Rn.
  4. 9(c)(i)2 marks· CAPE Physics Unit 2 · 2001 · Paper 1A particular radioactive element has a half-life of 100 years. Calculate its value of λ.
  5. 9(c)(ii)3 marks· CAPE Physics Unit 2 · 2001 · Paper 1After how many years will it take a whole year for this element to emit the same number of particles as it does in one day now? (1 year = 365 days).
  6. 3(a)(i)3 marks· CAPE Physics Unit 2 · 2001 · Paper 2Describe an experiment that can be performed in the laboratory to show the existence of β-particles.
  7. 9(a)(i)2 marks· CAPE Physics Unit 2 · 2001 · Paper 2Explain the meaning of the statement that ^14_6C has a half-life of 55 s.
  8. 9(a)(ii)2 marks· CAPE Physics Unit 2 · 2001 · Paper 2Explain the meaning of the statement that ^14_6C has a decay-constant of 1.25 × 10^(-2) s^(-1).
  9. 9(a)(iii)3 marks· CAPE Physics Unit 2 · 2001 · Paper 2Explain the meaning of the statement that the radioactive decay of ^14_6C is a random and spontaneous process.
  10. 9(b)1 mark· CAPE Physics Unit 2 · 2001 · Paper 2Name ONE external condition that does not affect radioactive decay.
  11. 9(c)(i)3 marks· CAPE Physics Unit 2 · 2001 · Paper 2Determine the number of nuclei present initially.
  12. 9(c)(ii)3 marks· CAPE Physics Unit 2 · 2001 · Paper 2Determine the decay constant from the data provided.
  13. 9(c)(iii)2 marks· CAPE Physics Unit 2 · 2001 · Paper 2Determine the half-life of the sample.
  14. 9(c)(iv)2 marks· CAPE Physics Unit 2 · 2001 · Paper 2Determine the activity after 8 hours.
  15. 9(c)(v)2 marks· CAPE Physics Unit 2 · 2001 · Paper 2Determine the number of radioactive nuclei remaining after 8 hours.
  16. 9(a)(i)2 marks· CAPE Physics Unit 2 · 2002 · Paper 1Explain what is meant by activity of a radioactive source, and state its corresponding unit.
  17. 9(a)(ii)2 marks· CAPE Physics Unit 2 · 2002 · Paper 1Explain what is meant by decay constant, and state its corresponding unit.
  18. 9(a)(iii)2 marks· CAPE Physics Unit 2 · 2002 · Paper 1Explain what is meant by half life, and state its corresponding unit.
  19. 9(b)(i)1 mark· CAPE Physics Unit 2 · 2002 · Paper 1Use the graph in Figure 11 to determine the background count rate.
  20. 9(b)(ii)1 mark· CAPE Physics Unit 2 · 2002 · Paper 1Use the graph in Figure 11 to determine the half life of the substance.
  21. 9(b)(iii)2 marks· CAPE Physics Unit 2 · 2002 · Paper 1Use the graph in Figure 11 to determine the decay constant.
  22. 8(a)(i)2 marks· CAPE Physics Unit 2 · 2002 · Paper 2In the radioactive decay law N = N0 e^(-λt), explain the meaning of EACH symbol.
  23. 8(a)(ii)3 marks· CAPE Physics Unit 2 · 2002 · Paper 2Show that N = N0 e^(-λt) can be written as N = N0 2^(-t / t_(1/2)), where t_(1/2) is the half-life.
  24. 8(a)(iv)2 marks· CAPE Physics Unit 2 · 2002 · Paper 2Explain why carbon dating is unable to provide accurate age estimates for very old materials.
  25. 8(b)6 marks· CAPE Physics Unit 2 · 2002 · Paper 2A nuclide 238_92 U decays to 214_82 X via FIVE successive decays, each emitting either an alpha particle or a beta particle. Determine the value of mass number A.
  26. 8(c)(i)4 marks· CAPE Physics Unit 2 · 2002 · Paper 2Calculate how long it will take for the number of atoms of each isotope to become equal.
  27. 8(c)(ii)2 marks· CAPE Physics Unit 2 · 2002 · Paper 2Sketch the decay curves for the two isotopes on the same axes.
  28. 9(d)2 marks· CAPE Physics Unit 2 · 2002 · Paper 2Show that a uranium-238 nucleus can disintegrate spontaneously with the emission of an alpha particle.
  29. 9(a)(i)3 marks· CAPE Physics Unit 2 · 2003 · Paper 2Explain what is meant by the terms, 'activity', 'decay constant' and 'half life' of a radioactive substance.
  30. 9(a)(ii)1 mark· CAPE Physics Unit 2 · 2003 · Paper 2State an equation relating the activity to the decay constant.
  31. 9(a)(iv)1 mark· CAPE Physics Unit 2 · 2003 · Paper 2What instrument could be used to detect Beta and Gamma radiation?
  32. 9(b)(ii)2 marks· CAPE Physics Unit 2 · 2003 · Paper 2A patient is injected with an 8.2 x 10^7 Bq sample of 99 Tc. How many gamma ray photons are initially produced within the patient each second?
  33. 9(b)(iii)2 marks· CAPE Physics Unit 2 · 2003 · Paper 2A small tumor that has collected ^99 Tc emits 38 gamma ray photons per second at a given time. How many ^99 Tc nuclei are located in the tumor at this time?
  34. 9(c)(i)a)2 marks· CAPE Physics Unit 2 · 2003 · Paper 2Calculate the fraction of the original ^40 K atoms remaining in the rock.
  35. 9(c)(i)b)2 marks· CAPE Physics Unit 2 · 2003 · Paper 2Calculate the number of half lives that has elapsed.
  36. 9(c)(i)c)1 mark· CAPE Physics Unit 2 · 2003 · Paper 2Calculate the age of the rock.
  37. 9(c)(ii)1 mark· CAPE Physics Unit 2 · 2003 · Paper 2From your answers in (c)(i) deduce the age of the solar system.
  38. 7(a)(i)2 marks· CAPE Physics Unit 2 · 2004 · Paper 1Complete the table giving the symbol, mass, and charge for alpha particles, beta particles, and gamma rays.
  39. 9(a)(i)5 marks· CAPE Physics Unit 2 · 2004 · Paper 2In the equation N = N_0 e^(-λt), explain the meaning of the symbols and define the terms activity, A, and half-life, t_(1/2).
  40. 9(a)(ii)3 marks· CAPE Physics Unit 2 · 2004 · Paper 2Show that the half-life of the sample can be written as (N ln 2) / A.
  41. 9(b)(i)2 marks· CAPE Physics Unit 2 · 2004 · Paper 2Determine the half-life of the sample from Figure 9.
  42. 9(b)(ii)2 marks· CAPE Physics Unit 2 · 2004 · Paper 2Determine the decay constant of the sample from Figure 9.
  43. 9(b)(iii)2 marks· CAPE Physics Unit 2 · 2004 · Paper 2Determine the activity at 1000 s from Figure 9.
  44. 8(a)(i)1 mark· CAPE Physics Unit 2 · 2005 · Paper 1Explain what is meant by half-life when referring to a radioactive source.
  45. 8(a)(ii)1 mark· CAPE Physics Unit 2 · 2005 · Paper 1Explain what is meant by decay constant when referring to a radioactive source.
  46. 8(b)(i)3 marks· CAPE Physics Unit 2 · 2005 · Paper 1Calculate the decay constant of Radium-226.
  47. 8(b)(ii)2 marks· CAPE Physics Unit 2 · 2005 · Paper 1The sample contains 5.0 x 10^16 such nuclei at t = 0. Calculate its activity at this time.
  48. 8(b)(iii)3 marks· CAPE Physics Unit 2 · 2005 · Paper 1Calculate the decay rate when the sample is 2.5 x 10^3 years old. [Data: 1 year = 3.2 x 10^7 s]
  49. 9(a)(i)3 marks· CAPE Physics Unit 2 · 2005 · Paper 1Beside EACH letter write the name of the parts labelled Q, S and T in Figure X.
  50. 9(a)(ii)1 mark· CAPE Physics Unit 2 · 2005 · Paper 1Describe the principle of the operation of a G-M tube.
  51. 9(a)(iii)2 marks· CAPE Physics Unit 2 · 2005 · Paper 1Explain why a mixture of argon and bromine gas is used in the tube.
  52. 9(b)(i)1 mark· CAPE Physics Unit 2 · 2005 · Paper 1Identify the type of radiation recorded at position A.
  53. 9(b)(ii)1 mark· CAPE Physics Unit 2 · 2005 · Paper 1Show on Figure XI the region where gamma radiation would be detected.
  54. 9(b)(iii)2 marks· CAPE Physics Unit 2 · 2005 · Paper 1If the distance from the source to the Geiger-Muller tube is about 15 cm, alpha-particles cannot be detected. Explain why.
  55. 3(a)6 marks· CAPE Physics Unit 2 · 2005 · Paper 2Add suitable data to the third column of Table 3, plot a straight line graph on the grid provided on page 11, and state the equation of the line plotted.
  56. 3(b)4 marks· CAPE Physics Unit 2 · 2005 · Paper 2Use the graph you plotted to determine the half-life of the sample.
  57. 9(a)(ii)2 marks· CAPE Physics Unit 2 · 2005 · Paper 2Explain why a neutron would penetrate farther into a sample of matter than an alpha particle of the same energy.
  58. 7(c)1 mark· CAPE Physics Unit 2 · 2006 · Paper 1Explain why the deflection diagram shown in Figure 9 is unrealistic.
  59. Q431 mark · multiple choice· CAPE Physics Unit 2 · 2007 · Paper 1Atoms undergo radioactive decay because
  60. Q441 mark · multiple choice· CAPE Physics Unit 2 · 2007 · Paper 1The diagram below shows the paths of two types of radioactive emissions, P and Q, in a uniform magnetic field, which is directed into the page. What are P and Q?
  61. Q451 mark · multiple choice· CAPE Physics Unit 2 · 2007 · Paper 1A radioactive nuclide is represented by the symbol {}^{76}_{33}\text{P}. It decays into a nuclide of element Q by beta decay. Q then decays into a nuclide of element R by alpha decay and releases gamma radiation. What…
  62. 3(a)1 mark· CAPE Physics Unit 2 · 2007 · Paper 2Calculate and fill in the missing ln I values in Table 3.
  63. 3(b)(i)4 marks· CAPE Physics Unit 2 · 2007 · Paper 2Plot a graph of ln I against x on the provided grid and draw the best-fit line through the points.
  64. 3(b)(ii)a)2 marks· CAPE Physics Unit 2 · 2007 · Paper 2From your graph, determine the linear absorption coefficient μ.
  65. 3(b)(ii)b)2 marks· CAPE Physics Unit 2 · 2007 · Paper 2From your graph, determine the initial intensity I₀.
  66. 3(c)1 mark· CAPE Physics Unit 2 · 2007 · Paper 2Explain how the value of I₀ can be measured directly.
  67. 8(a)(i)4 marks· CAPE Physics Unit 2 · 2007 · Paper 2Describe, with a labelled diagram of the apparatus, an experiment to show that radioactive decay is a random process, using a small long-lived radium source. Describe how to present the data and state the conclusion.
  68. 8(a)(ii)2 marks· CAPE Physics Unit 2 · 2007 · Paper 2State the mathematical relationship between the number of parent nuclei present and the activity of a radioactive source.
  69. 8(a)(iii)2 marks· CAPE Physics Unit 2 · 2007 · Paper 2Explain the meaning of 'half-life' and state the equation relating half-life to the decay constant λ.
  70. 8(b)(i)3 marks· CAPE Physics Unit 2 · 2007 · Paper 2Calculate the number of parent atoms present at time t = 0.
  71. 8(b)(ii)2 marks· CAPE Physics Unit 2 · 2007 · Paper 2Determine the activity of the source after 9 years.
  72. 8(b)(iii)3 marks· CAPE Physics Unit 2 · 2007 · Paper 2Calculate the activity of the source after 12 years.
  73. 8(b)(iv)4 marks· CAPE Physics Unit 2 · 2007 · Paper 2If the source cannot be safely disposed of until its activity falls below 100 Bq, calculate the minimum number of years it must be stored.
  74. Q411 mark · multiple choice· CAPE Physics Unit 2 · 2007 (Specimen) · Paper 1The decay constant of a radioactive sample of radon gas 1 \times 10^{-2}\text{ s}^{-1}. If there were 1.6 \times 10^5\text{ atoms} of radon gas present at a certain time, T, how much time must elapse before there…
  75. Q431 mark · multiple choice· CAPE Physics Unit 2 · 2007 (Specimen) · Paper 1A radioactive substance emits a type of ionising radiation, P, with the following properties: mass: zero speed: 3 \times 10^8\text{ m s}^{-1} Which of the following statement about P is true? I. P is not deflected…
  76. Q441 mark · multiple choice· CAPE Physics Unit 2 · 2007 (Specimen) · Paper 1An archaeologist finds an ancient wooden relic and obtains its count rate as 20\text{ counts per minute per gram} of sample. The count rate obtained from the bark of a living tree is…
  77. Q451 mark · multiple choice· CAPE Physics Unit 2 · 2007 (Specimen) · Paper 1What are the parts labelled w, x and y?
  78. Q421 mark · multiple choice· CAPE Physics Unit 2 · 2008 (Rest of Region) · Paper 1A radioactive element has a half life period of 1600\text{ years}. After 6400\text{ years}, what fraction of a sample of this element will remain?
  79. Q431 mark · multiple choice· CAPE Physics Unit 2 · 2008 (Rest of Region) · Paper 1A radioactive nucleus is represented by ^{227}_{85}\text{X}. It emits an \alpha-particle and a \gamma ray to form a different nucleus of element Y. Which of the following represents the new nucleus?
  80. Q451 mark · multiple choice· CAPE Physics Unit 2 · 2008 (Rest of Region) · Paper 1A uranium nucleus ^{238}_{92}\text{U} decays by a series of emissions into ^{222}_{86}\text{Rn}. Which of the following emissions could have occurred during the series of decay from uranium-238 to radon-222?
  81. 6(b)(ii)3 marks· CAPE Physics Unit 2 · 2008 (Rest of Region) · Paper 2Calculate the number of radon atoms present at that instant if the half-life of radon is 55 s.
  82. 6(b)(iii)3 marks· CAPE Physics Unit 2 · 2008 (Rest of Region) · Paper 2Find the rate of energy release (in watts) for the sample given that each decay releases 6.3 MeV and the activity is 4500 Bq.
  83. Q381 mark · multiple choice· CAPE Physics Unit 2 · 2008 (T&T) · Paper 1A radium source is placed in a magnetic field as shown below. The field acts into the page. At what position would a \beta-particle be detected?
  84. Q401 mark · multiple choice· CAPE Physics Unit 2 · 2008 (T&T) · Paper 1What does \lambda represent in the equation, N = N_0 e^{(-\lambda t)}?
  85. Q411 mark · multiple choice· CAPE Physics Unit 2 · 2008 (T&T) · Paper 1A freshly made sample of radioactive material gives a count rate of 8000\text{ counts per minute}. After twenty days, it gives a count-rate of 500\text{ counts per minute}. What is the half-life of the material?
  86. Q411 mark · multiple choice· CAPE Physics Unit 2 · 2009 · Paper 1A radium source is placed in a magnetic field as shown below. The field acts into the page. At what position would a \beta-particle be detected?
  87. Q421 mark · multiple choice· CAPE Physics Unit 2 · 2009 · Paper 1Item 42 refers to the following diagram which shows how the count rate of a certain sample of radioactive material varies with time. What is the approximate half-life of the sample?
  88. Q431 mark · multiple choice· CAPE Physics Unit 2 · 2009 · Paper 1Radioactive lead ^{211}_{82}\text{Pb} decays by two beta particles and one alpha particle. What is the resulting nuclide?
  89. Q441 mark · multiple choice· CAPE Physics Unit 2 · 2009 · Paper 1The following statements refer to radioactive decay. I. It is a random process II. It is a spontaneous process III. It is dependent on the chemical combination of radioactive elements IV. It increases with temperature…
  90. Q451 mark · multiple choice· CAPE Physics Unit 2 · 2009 · Paper 1The half-life of a sample of radioactive substance is 100\text{ years}. What is its decay constant?
  91. 6(a)5 marks· CAPE Physics Unit 2 · 2009 · Paper 2Explain the terms 'decay constant' (lambda) and 'half life' (T_1/2). Starting with N = N0 * e^(-lambda * t), derive an equation relating these two quantities.
  92. 6(b)(i)1 mark· CAPE Physics Unit 2 · 2009 · Paper 2Calculate the decay constant in units of s^-1.
  93. 6(b)(ii)2 marks· CAPE Physics Unit 2 · 2009 · Paper 2Calculate the number of atoms present in a 1.0 mg sample of sodium-24.
  94. 6(b)(iii)2 marks· CAPE Physics Unit 2 · 2009 · Paper 2Calculate the activity of a 1.0 mg pure sample of sodium-24.
  95. 6(c)5 marks· CAPE Physics Unit 2 · 2009 · Paper 2A small volume of sodium-24 solution having an initial activity of 1.2 * 10^4 disintegrations per minute was injected into a patient's bloodstream. After 30 hours, the activity of 1.0 cm^3 of the blood was measured as…
  96. Q371 mark · multiple choice· CAPE Physics Unit 2 · 2010 · Paper 1An experiment to investigate the absorption of \gamma-rays in air using ^{60}\text{Co} as the source is illustrated in the diagram below. x is the distance between the source and region in the G-M tube where…
  97. Q411 mark · multiple choice· CAPE Physics Unit 2 · 2010 · Paper 1A radium source is placed in a magnetic field as shown below. The magnetic field acts into the page. At what position would a \beta-particle be detected?
  98. Q421 mark · multiple choice· CAPE Physics Unit 2 · 2010 · Paper 1The activity of a radioactive isotope is found to fall to \frac{1}{16} of its initial value in 2\text{ hrs}. What is the half-life of the isotope?
  99. Q441 mark · multiple choice· CAPE Physics Unit 2 · 2010 · Paper 1The activity of a radioactive source is
  100. Q451 mark · multiple choice· CAPE Physics Unit 2 · 2010 · Paper 1In medicine radioactive isotopes are often used as tracers to help in locating blockages in the human body. Which of the following isotopes would be MOST suitable for such an application?
  101. 3(a)7 marks· CAPE Physics Unit 2 · 2010 · Paper 2Describe how to accurately measure the half-life of Radon-220, an α-emitter with a short half-life easily separated from its powdered solid parent, detailing required apparatus, procedure, and data processing.
  102. 3(b)(i)5 marks· CAPE Physics Unit 2 · 2010 · Paper 2Calculate how many α-particles would be emitted by a 4 mg sample of ²²⁰₈₆Rn in 108 seconds.
  103. 3(b)(ii)3 marks· CAPE Physics Unit 2 · 2010 · Paper 2A laboratory is deemed safe after a Radon-220 leak when the activity decreases to less than 0.1% of its original value. Calculate the MINIMUM number of minutes for which the laboratory must remain closed.
  104. Q411 mark · multiple choice· CAPE Physics Unit 2 · 2011 · Paper 1The activity of a radioactive source is
  105. Q441 mark · multiple choice· CAPE Physics Unit 2 · 2011 · Paper 1Which of the following statements are true about radioactive decay? I. It is a random process. II. It is a spontaneous process. III. It is dependent on the chemical combination of radioactive elements. IV. It increases…
  106. Q451 mark · multiple choice· CAPE Physics Unit 2 · 2011 · Paper 1The half-life of a sample of radioactive substance is 100 years. What is its decay constant?
  107. 3(a)3 marks· CAPE Physics Unit 2 · 2011 · Paper 2Identify EACH type of radiation stopped by the respective materials in Figure 3 (a) by writing the name of the radiation next to the corresponding arrow.
  108. 3(b)(i)1 mark· CAPE Physics Unit 2 · 2011 · Paper 2Express the relationship between intensity, C, of gamma rays and corrected distance, (d - x), mathematically.
  109. 3(b)(ii)2 marks· CAPE Physics Unit 2 · 2011 · Paper 2Show that a straight line graph would be expected if d were plotted against 1 / sqrt(C).
  110. 3(b)(iii)2 marks· CAPE Physics Unit 2 · 2011 · Paper 2Complete Table 1 to show the data that must be plotted to obtain the graph of d against 1 / sqrt(C).
  111. 3(b)(iv)5 marks· CAPE Physics Unit 2 · 2011 · Paper 2On the graph paper provided on page 11, plot the graph of d against 1 / sqrt(C).
  112. 3(b)(v)2 marks· CAPE Physics Unit 2 · 2011 · Paper 2Determine, from the graph, the value of x.
  113. Q421 mark · multiple choice· CAPE Physics Unit 2 · 2012 · Paper 1The activity of a radioactive source is the
  114. Q431 mark · multiple choice· CAPE Physics Unit 2 · 2012 · Paper 1The following statements refer to radioactive decay. I. It is a random process. II. It is a spontaneous process. III. It is dependent on the chemical combination of radioactive elements. IV. It increases with…
  115. Q441 mark · multiple choice· CAPE Physics Unit 2 · 2012 · Paper 1A freshly made sample of radioactive material gives a count rate of 8000\text{ counts per minute}. After twenty days, it gives a count rate of 500\text{ counts per minute}. What is the half-life of the material?
  116. Q451 mark · multiple choice· CAPE Physics Unit 2 · 2012 · Paper 1In medicine, radioactive isotopes are often used as tracers to help in locating blockages in the human body. Which of the following isotopes would be MOST suitable for such an application?
  117. 6(a)(i)2 marks· CAPE Physics Unit 2 · 2012 · Paper 2State the number of protons, neutrons, and electrons in a neutral atom of 226_86 Rn.
  118. 6(a)(ii)2 marks· CAPE Physics Unit 2 · 2012 · Paper 2Explain what is meant by the term 'isotope'.
  119. 6(b)3 marks· CAPE Physics Unit 2 · 2012 · Paper 2Define 'half-life' and 'decay constant, λ' for a radioactive nucleus, and write an equation relating the two quantities.
  120. 6(c)(i)2 marks· CAPE Physics Unit 2 · 2012 · Paper 2Determine the number of nuclei in the 3.50 μg sample of pure 11_6 C at t = 0.
  121. 6(c)(ii)2 marks· CAPE Physics Unit 2 · 2012 · Paper 2Determine the decay constant of the carbon-11 sample.
  122. 6(c)(iii)2 marks· CAPE Physics Unit 2 · 2012 · Paper 2Determine the activity of the sample at t = 0.
  123. 6(c)(iv)2 marks· CAPE Physics Unit 2 · 2012 · Paper 2Determine the activity of the carbon-11 after 8 hours.
  124. Q421 mark · multiple choice· CAPE Physics Unit 2 · 2013 · Paper 1A radium source is placed in a magnetic field as shown below. The field acts into the page. At what position would a \beta-particle be detected?
  125. Q431 mark · multiple choice· CAPE Physics Unit 2 · 2013 · Paper 1The activity of a radioactive isotope is found to fall to \frac{1}{16} of its initial value in 2\text{ hrs}. What is the half-life of the isotope?
  126. Q441 mark · multiple choice· CAPE Physics Unit 2 · 2013 · Paper 1Which of the following statements are true about radioactive decay? I. It is a random process. II. It is a spontaneous process. III. It is dependent on the chemical combination of radioactive elements. IV. It increases…
  127. Q451 mark · multiple choice· CAPE Physics Unit 2 · 2013 · Paper 1The half-life of a sample of radioactive substance is 100\text{ years}. What is its decay constant?
  128. 6(a)1 mark· CAPE Physics Unit 2 · 2013 · Paper 2Write the equation describing this decay.
  129. 6(b)(iii)3 marks· CAPE Physics Unit 2 · 2013 · Paper 2Given that t_1/2 is the half-life of a radioactive sample, use the decay equation from Part (a) to show that t_1/2 = 0.69 / λ.
  130. 6(d)(i)1 mark· CAPE Physics Unit 2 · 2013 · Paper 2State what is meant by the term 'activity' of a radioactive nucleus and write its expression in mathematical form.
  131. 6(d)(ii)2 marks· CAPE Physics Unit 2 · 2013 · Paper 2A sample of Francium-221 contains 10^12 atoms. Calculate its activity.
  132. Q401 mark · multiple choice· CAPE Physics Unit 2 · 2014 · Paper 1What does \lambda in the equation N = N_0\ e^{-\lambda t} represent?
  133. Q421 mark · multiple choice· CAPE Physics Unit 2 · 2014 · Paper 1Radioactive lead, ^{211}_{82}\text{Pb}, decays by two beta particles and one alpha particle. What is the resulting nuclide?
  134. Q431 mark · multiple choice· CAPE Physics Unit 2 · 2014 · Paper 1The half-life of a sample of radioactive substance is 100\text{ years}. What is its decay constant?
  135. Q441 mark · multiple choice· CAPE Physics Unit 2 · 2014 · Paper 1The activity of a radioactive source is
  136. Q451 mark · multiple choice· CAPE Physics Unit 2 · 2014 · Paper 1In medicine, radioactive isotopes are often used as tracers to help in locating blockages in the human body. Which of the following isotopes would be MOST suitable for such an application?
  137. 3(a)5 marks· CAPE Physics Unit 2 · 2014 · Paper 2Write a brief description of an experiment to determine the half-life of a radioactive sample.
  138. 3(b)3 marks· CAPE Physics Unit 2 · 2014 · Paper 2State THREE properties of a radioisotope which would make it suitable for use in radiotherapy.
  139. 3(d)5 marks· CAPE Physics Unit 2 · 2014 · Paper 2Carbon-14 decays to nitrogen by beta emission with a half-life of 5730 years. Determine the percentage of carbon-14, relative to the initial amount, which would remain after 20 000 years.
  140. Q391 mark · multiple choice· CAPE Physics Unit 2 · 2015 · Paper 1Which of the following equations represents the radioactive disintegration of Polonium-210 by \alpha-emission to a stable isotope of lead?
  141. Q401 mark · multiple choice· CAPE Physics Unit 2 · 2015 · Paper 1Which of the following statements is true?
  142. Q411 mark · multiple choice· CAPE Physics Unit 2 · 2015 · Paper 1Radioactive decay is the
  143. Q431 mark · multiple choice· CAPE Physics Unit 2 · 2015 · Paper 1The activity of a radioactive isotope is found to fall to \frac{1}{16} of its initial value in 2\text{ hours}. What is the half-life of the isotope?
  144. Q441 mark · multiple choice· CAPE Physics Unit 2 · 2015 · Paper 1Which of the following statements are true about radioactive decay? I. It is a random process. II. It is a spontaneous process. III. It is dependent on the chemical combination of radioactive elements. IV. It increases…
  145. 3(a)4 marks· CAPE Physics Unit 2 · 2015 · Paper 2Complete Table 3 to indicate TWO properties and TWO reasons why a radioisotope such as technetium-99m can be used in this way.
  146. 3(b)(i)2 marks· CAPE Physics Unit 2 · 2015 · Paper 2Complete Table 4 by calculating and inserting appropriate values in the relevant columns for A/A_0 and \ln(A/A_0).
  147. 3(b)(ii)4 marks· CAPE Physics Unit 2 · 2015 · Paper 2On the grid provided in Figure 5, plot a graph of \ln(A/A_0) against time, t (in hours), and draw the best straight line through the points.
  148. 3(b)(iii)3 marks· CAPE Physics Unit 2 · 2015 · Paper 2Use your graph to find the decay constant of technetium-99m.
  149. 3(b)(iv)2 marks· CAPE Physics Unit 2 · 2015 · Paper 2Use the decay constant to calculate the half-life, t_{1/2}, of technetium-99m.
  150. Q431 mark · multiple choice· CAPE Physics Unit 2 · 2016 · Paper 1Radioactive decay is the
  151. Q441 mark · multiple choice· CAPE Physics Unit 2 · 2016 · Paper 1Uranium-238, ^{238}_{92}\text{U} decays by one alpha particle and one beta particle. What is the resulting nuclide?
  152. Q451 mark · multiple choice· CAPE Physics Unit 2 · 2016 · Paper 1In medicine, radioactive isotopes are often used as tracers to help in locating blockages in the human body. Which of the following isotopes would be MOST suitable for such an application?
  153. 6(c)5 marks· CAPE Physics Unit 2 · 2016 · Paper 2Cobalt-60 has a half-life of 5.27 years. Beginning with an initial sample of 200 grams of pure Co-60, determine how many grams of nickel would be found after three years. Neglect the mass equivalence of the energy in…
  154. Q341 mark · multiple choice· CAPE Physics Unit 2 · 2017 · Paper 1The equation which represents the radioactive change of a ^{60}_{27}\text{Co} nucleus by \beta-emission is
  155. Q401 mark · multiple choice· CAPE Physics Unit 2 · 2017 · Paper 1Which of the following statements are true about radioactive decay? I. It is a random process. II. It is a spontaneous process. III. It is dependent on the chemical combination of radioactive elements.
  156. Q441 mark · multiple choice· CAPE Physics Unit 2 · 2017 · Paper 1What is the half-life for a radioactive isotope containing 10^{20} atoms with a decay constant of 1.60 \times 10^{-5}\text{ s}^{-1}?
  157. Q431 mark · multiple choice· CAPE Physics Unit 2 · 2018 · Paper 1Radioactive decay is the
  158. Q441 mark · multiple choice· CAPE Physics Unit 2 · 2018 · Paper 1A sample of radioactive material contains initially 2.0 \times 10^{18}\text{ atoms}. The material decays by \alpha-emission and has a half-life of 3.0 \times 10^{10}\text{ s}. The initial activity of the sample is
  159. Q451 mark · multiple choice· CAPE Physics Unit 2 · 2018 · Paper 1What does \lambda in the equation N = N_0\, e^{(-\lambda t)} represent?
  160. 3(a)(i)1 mark· CAPE Physics Unit 2 · 2018 · Paper 2Write the exponential decay equation for radioactive materials.
  161. 3(a)(ii)2 marks· CAPE Physics Unit 2 · 2018 · Paper 2Identify the decay constant in the equation in (a)(i) and state the units in which it is usually quoted.
  162. 3(b)(i)3 marks· CAPE Physics Unit 2 · 2018 · Paper 2On the grid provided in Figure 4, plot a graph of count rate versus elapsed time, and draw a best smooth curve through the points.
  163. 3(b)(ii)1 mark· CAPE Physics Unit 2 · 2018 · Paper 2Draw the tangent to the curve at the point where t = 0 and produce the tangent to intersect the t-axis.
  164. 3(b)(iii)1 mark· CAPE Physics Unit 2 · 2018 · Paper 2Read off the value of t at the point of intersection.
  165. 3(c)1 mark· CAPE Physics Unit 2 · 2018 · Paper 2It can be shown that the half-life is 0.69τ where τ is the value of t at the point of intersection with the tangent. Calculate the half-life using this formula.
  166. 3(d)2 marks· CAPE Physics Unit 2 · 2018 · Paper 2Determine the half-life by directly reading off from your graph and suggest a reason for any discrepancy between this value and the value calculated in (c).
  167. 3(e)4 marks· CAPE Physics Unit 2 · 2018 · Paper 2If the initial sample contained 50 grams of the radioisotope at the start of the experiment, determine the quantity remaining after 4 hours.
  168. Q341 mark · multiple choice· CAPE Physics Unit 2 · 2019 · Paper 1The equation which represents the radioactive change of a ^{60}_{27}\text{Co} nucleus by \beta^- emission is
  169. Q381 mark · multiple choice· CAPE Physics Unit 2 · 2019 · Paper 1In medicine, radioactive isotopes are often used as tracers to assist in locating blockages in the human body. Which of the following isotopes would be MOST suitable for such an application? \begin{tabular}{|c|c|c|}…
  170. Q401 mark · multiple choice· CAPE Physics Unit 2 · 2019 · Paper 1Uranium-238, ^{238}_{92}\text{U}, decays by one alpha particle and one beta particle. What is the resulting nuclide?
  171. Q441 mark · multiple choice· CAPE Physics Unit 2 · 2019 · Paper 1What is the half-life for a radioactive isotope containing 1020 atoms with a decay constant of 1.60 \times 10^{-5}\text{ hour}^{-1}?
  172. Q451 mark · multiple choice· CAPE Physics Unit 2 · 2019 · Paper 1The activity of a radioactive isotope is found to fall to 1/16 of its initial value in 2 hours. What is the half-life of the isotope?
  173. 3(a)(i)2 marks· Physics · Unit 2 Q3 3(a)(i)Determine log₁₀R for EACH value of x and complete Row 3 of Table 3.
  174. 3(a)(i)2 marks· Physics · Unit 2 Q3 3(a)(i)Define Activity and state the unit in which it is measured.
  175. 3(a)(ii)2 marks· Physics · Unit 2 Q3 3(a)(ii)Define Decay constant and state the unit in which it is measured.
  176. 3(a)(ii)3 marks· Physics · Unit 2 Q3 3(a)(ii)Using the axes provided in Figure 6 on page 17, plot a graph of log₁₀R against x, ensuring that the x-axis extends to x = 3.0 mm. Draw the line of best fit through the points.
  177. 3(a)(iii)2 marks· Physics · Unit 2 Q3 3(a)(iii)Define Half-life and state the unit in which it is measured.
  178. 3(a)(iii)3 marks· Physics · Unit 2 Q3 3(a)(iii)Deduce the count rate at x = 2.8 mm.
  179. 3(a)(iv)2 marks· Physics · Unit 2 Q3 3(a)(iv)Explain why the lower count rate values are more likely to be inaccurate.
  180. 3(b)(i)2 marks· Physics · Unit 2 Q3 3(b)(i)Complete Column 3 and Column 4 of Table 2.
  181. 3(b)(i)7 marks· Physics · Unit 2 Q3 3(b)(i)Calculate the half-life of Iodine-123, in hours.
  182. 3(b)(ii)4 marks· Physics · Unit 2 Q3 3(b)(ii)On the grid provided in Figure 5 on page 17, plot a graph of ln (A/A₀) versus time, t. Draw the line of best fit through the points.
  183. 3(b)(iii)5 marks· Physics · Unit 2 Q3 3(b)(iii)Determine the gradient of the graph in (b)(ii) and use it to find the half-life of Technetium-99m.
  184. 3(b)(iv)4 marks· Physics · Unit 2 Q3 3(b)(iv)Use your results from (b)(iii) to calculate the time, t, required for the activity in the patient's body to decrease to one per cent of its value at the time of injection.
  185. 3(b)(v)1 mark· Physics · Unit 2 Q3 3(b)(v)Express the activity in disintegrations per second when the activity has decayed to one per cent of its initial value.
  186. 3(b)(vi)2 marks· Physics · Unit 2 Q3 3(b)(vi)State TWO properties of radioactive tracers that make them suitable for use in nuclear imaging.
  187. 3(c)(i)4 marks· Physics · Unit 2 Q3 3(c)(i)Complete Column 3 and Column 4 in Table 2.
  188. 3(c)(i)4 marks· Physics · Unit 2 Q3 3(c)(i)Describe how radiocarbon dating is used to determine the age of ancient organic materials.
  189. 3(c)(ii)4 marks· Physics · Unit 2 Q3 3(c)(ii)On the grid provided in Figure 3 on page 19, plot a graph of ln(N/N_0) versus time, t. Draw the line of best fit through the points.
  190. 3(c)(ii)4 marks· Physics · Unit 2 Q3 3(c)(ii)A radioactive isotope of carbon found in a sample of 6.02 × 10^23 atoms of living wood has a decay constant of 3.84 × 10^–12 s^–1. Calculate its half-life in years.
  191. 3(c)(iii)3 marks· Physics · Unit 2 Q3 3(c)(iii)Readings are no longer reliable when they fall below 2100 counts per minute. Use the graph in (c)(ii) to determine the period of reliability for a sample that is prepared and delivered with a starting count rate of 3000…
  192. 3(c)(iii)3 marks· Physics · Unit 2 Q3 3(c)(iii)Calculate the rate of decay of C-14 in this sample.
  193. 3(c)(iv)4 marks· Physics · Unit 2 Q3 3(c)(iv)State TWO properties of a radioisotope which might make it suitable for use in nuclear medicine, giving an explanation in EACH case as to why that particular property makes it useful.

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