8.6 Nuclear Physics - Mass and Energy - Qs

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8.6 Nuclear Physics - Mass and Energy – Questions

Q1. (a) (i) Explain what is meant by the term binding energy for a nucleus.

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(ii) Sketch on the axes a graph of the average binding energy per nucleon against nucleon number A, giving approximate values of the scale on each axis.

(5)

(b) Use your graph to explain why energy is released when a neutron collides with a nucleus causing fission.

(2)

(c) Neutrons are released when nuclear fission occurs in . Some of these neutrons induce further fission, others are absorbed without further fission and others escape from the surface of the material. The average number of neutrons released per fission is 2.5, of which at least one must produce further fission if a chain reaction is to be sustained.

Explain how a chain reaction can occur only if the piece of uranium has a certain minimum mass (the critical mass).

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(Total 10 marks)

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Q2. (a) Scattering experiments are used to investigate the nuclei of gold atoms.

In one experiment, alpha particles, all of the same energy (monoenergetic), are incident on a foil made from a single isotope of gold.

(i) State the main interaction when an alpha particle is scattered by a gold nucleus.

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(ii) The gold foil is replaced with another foil of the same size made from a mixture of isotopes of gold. Nothing else in the experiment is changed.

Explain whether or not the scattering distribution of the monoenergetic alpha particles remains the same.

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(b) Data from alpha−particle scattering experiments using elements other than gold allow scientists to relate the radius R, of a nucleus, to its nucleon number, A. The graph shows the relationship obtained from the data in a graphical form, which obeys

the relationship R = r0

(i) Use information from the graph to show that r0 is about 1.4 × 10–15 m.

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(1)

(ii) Show that the radius of a V nucleus is about 5 × 10–15 m.

(2)

(c) Calculate the density of a V nucleus.

State an appropriate unit for your answer.

density ____________________ unit __________ (3)

(Total 8 marks)

Q3. (a) Sketch a graph of binding energy per nucleon against nucleon number for the

naturally occurring nuclides on the axes given in the figure below. Add values and a unit to the binding energy per nucleon axis.

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(4)

(b) Use the graph to explain how energy is released when some nuclides undergo fission and when other nuclides undergo fusion.

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(Total 7 marks)

Q4. In the research into nuclear fusion one of the most promising reactions is between

deuterons and tritium nuclei in a gaseous plasma. Although deuterons can be relatively easily extracted from sea water, tritium is difficult to produce. It can, however, be

produced by bombarding lithium-6 with neutrons. The two reactions are summarised as:

+ energy

+ energy

Masses of reactants:

= 1.008665u

= 2.013553u

= 3.016049u

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= 4.002603u

= 6.015122u

1u is equivalent to 1.66 × 10–27 kg or 931 MeV

(a) (i) Explain why the atomic mass unit, u, may be quoted in kg or MeV.

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(ii) Calculate the maximum amount of energy, in MeV, released when 1.0 kg of lithium-6 is bombarded by neutrons.

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energy released ______________________ MeV (5)

(iii) Suggest why the lithium-6 reaction could be thought to be self-sustaining once the deuteron-tritium reaction is underway.

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(b) (i) In order to fuse, a deuteron and a tritium nucleus must approach one another to within approximately 1.5 × 10–15 m. Calculate the minimum total initial kinetic energy that these nuclei must have.

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minimum total kinetic energy of nuclei ______________________ J (3)

(ii) Show that a temperature of approximately 4 × 109 K would be sufficient to enable this fusion to occur in a gaseous plasma.

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(iii) Explain in terms of the forces acting on nuclei why the deuteron-tritium mixture must be so hot in order to achieve the fusion reaction.

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(Total 18 marks)

Q5. The Sun’s energy is produced by the fusion of protons. Near the Sun’s surface the protons have a mean kinetic energy of 0.75 eV which is too low for fusion to take place. The core, however, has a temperature of about 1.5 × 106 K and a pressure of about 1.0 × 1016 Pa. This core consists of a plasma of (mainly) protons. Within the core the density, pressure and temperature of the proton plasma are sufficiently high for nuclear fusion to occur. The energy is thought to be produced mainly by a cycle called the hydrogen cycle. The overall effect in one cycle is that 4 protons fuse to form a helium nucleus. The total mass of hydrogen that fuses each second is 7.0 × 1011 kg of which about 5.0 × 109 kg per second is converted into energy that is radiated.

When answering the following questions assume, where necessary, that the plasma behaves like an ideal gas.

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(a) (i) Use the mean value of the kinetic energy of protons near the Sun’s surface to calculate the temperature near its surface.

temperature near the Sun’s surface ____________________ K (3)

(ii) Calculate the closest distance of approach for two protons near the Sun’s surface.

closest distance of approach ____________________ m (3)

(iii) Explain why fusion cannot occur near the surface.

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(b) (i) Calculate the number of protons in each cubic metre of the Sun’s core.

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number of protons ____________________ (3)

(ii) Calculate the density of the Sun’s core.

density of the Sun’s core ____________________ kg m–3

(2)

(c) (i) Show that the data given in the passage in question (a) suggest that every second, about 4 × 1038 protons fuse to form helium nuclei.

(2)

(ii) The total binding energy of a helium nucleus is 4.5 × 10–12 J. Determine with an appropriate calculation whether the mass that is converted into radiant energy, stated in the passage, is consistent with this value.

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(Total 20 marks)

Q6. The isotope of uranium, , decays into a stable isotope of lead, , by means of a series of α and β– decays.

(a) In this series of decays, α decay occurs 8 times and β– decay occurs n times. Calculate n.

answer = ____________________ (1)

(b) (i) Explain what is meant by the binding energy of a nucleus.

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(ii) Figure 1 shows the binding energy per nucleon for some stable nuclides.

Figure 1

Use Figure 1 to estimate the binding energy, in MeV, of the nucleus.

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answer = ____________________ MeV (1)

(c) The half-life of is 4.5 × 109 years, which is much larger than all the other half-lives of the decays in the series.

A rock sample when formed originally contained 3.0 × 1022 atoms of and no

atoms.

At any given time most of the atoms are either or with a negligible number of atoms in other forms in the decay series.

(i) Sketch on Figure 2 graphs to show how the number of atoms and the

number of atoms in the rock sample vary over a period of 1.0 × 1010 years from its formation. Label your graphs U and Pb.

Figure 2

(2)

(ii) A certain time, t, after its formation the sample contained twice as many

atoms as atoms.

Show that the number of atoms in the rock sample at time t was 2.0 ×

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1022.

(1)

(ii) Calculate t in years.

answer = ____________________ years (3)

(Total 10 marks)

Q7. (a) The mass of a nucleus is M.

(i) If the mass of a proton is mp, and the mass of a neutron is mn, give an expression for the mass difference ∆m of this nucleus.

∆m = ________________________________________________________

(ii) Give an expression for the binding energy per nucleon of this nucleus, taking the speed of light to be c.

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(b) The figure below shows an enlarged portion of a graph indicating how the binding energy per nucleon of various nuclides varies with their nucleon number.

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(i) State the value of the nucleon number for the nuclides that are most likely to be stable. Give your reasoning.

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(ii) When fission of uranium 235 takes place, the nucleus splits into two roughly equal parts and approximately 200 Me V of energy is released. Use information from the figure above to justify this figure, explaining how you arrive at your answer.

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(Total 7 marks)

Q8. In stars, helium-3 and helium-4 are formed by the fusion of hydrogen nuclei. As the temperature rises, a helium-3 nucleus and a helium-4 nucleus can fuse to produce beryllium-7 with the release of energy in the form of gamma radiation.

The table below shows the masses of these nuclei.

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Nucleus Mass / u

Helium-3 3.01493

Helium-4 4.00151

Beryllium-7 7.01473

(a) (i) Calculate the energy released, in J, when a helium-3 nucleus fuses with a helium-4 nucleus.

energy released ____________________ J (4)

(ii) Assume that in each interaction the energy is released as a single gamma-ray photon.

Calculate the wavelength of the gamma radiation.

wavelength ____________________ m (3)

(b) For a helium-3 nucleus and a helium-4 nucleus to fuse they need to be separated by no more than 3.5 × 10–15 m.

(i) Calculate the minimum total kinetic energy of the nuclei required for them to reach a separation of 3.5 × 10–15 m.

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total kinetic energy ____________________ J (3)

(ii) Calculate the temperature at which two nuclei with the average kinetic energy for that temperature would be able to fuse. Assume that the two nuclei have equal kinetic energy.

temperature ____________________ K (3)

(c) Scientists continue to try to produce a viable fusion reactor to generate energy on Earth using reactors like the Joint European Torus (JET). The method requires a plasma that has to be raised to a suitable temperature for fusion to take place.

(i) State two nuclei that are most likely to be used to form the plasma of a fusion reactor.

1. ____________________________________________________________

2. ____________________________________________________________ (2)

(ii) State one method which can be used to raise the temperature of the plasma to a suitable temperature.

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(Total 16 marks)

Q9. (a) (i) Complete the equation below which represents the induced fission of a

nucleus of uranium .

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(ii) The graph shows the binding energy per nucleon plotted against nucleon number A.

Mark on the graph the position of each of the three nuclei in the equation.

(iii) Hence determine the energy released in the fission process represented by the equation.

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(b) (i) Use your answer to part (a)(iii) to estimate the energy released when 1.0 kg of uranium, containing 3% by mass of , undergoes fission.

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(ii) Oil releases approximately 50 MJ of heat per kg when it is burned in air. State and explain one advantage and one disadvantage of using nuclear fuel to produce electricity.

advantage _____________________________________________________

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disadvantage ___________________________________________________

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(Total 12 marks)

Q10. In a geothermal power station, water is pumped through pipes into an underground region of hot rocks. The thermal energy of the rocks heats the water and turns it to steam at high pressure. The steam then drives a turbine at the surface to produce electricity.

(a) Water at 21°C is pumped into the hot rocks and steam at 100°C is produced at a rate of 190 kg s–1.

(i) Show that the energy per second transferred from the hot rocks to the power station in this process is at least 500 MW.

specific heat capacity of water = 4200 J kg–1 K–1

specific latent heat of steam = 2.3 × 106 J kg–1

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(ii) The hot rocks are estimated to have a volume of 4.0 × 106 m3. Estimate the fall of temperature of these rocks in one day if thermal energy is removed from them at the rate calculated in part (i) without any thermal energy gain from deeper underground.

specific heat capacity of the rocks = 850 J kg–1 K–1

density of the rocks = 3200 kg m–3

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(b) Geothermal energy originates as energy released in the radioactive decay of the

uranium isotope U deep inside the Earth. Each nucleus that decays releases 4.2 MeV.

Calculate the mass of U that would release energy at a rate of 500 MW.

half-life of U = 4.5 × 109 years

molar mass of U = 0.238 kg mol–1

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(Total 12 marks)

Q11. (a) Calculate the binding energy, in MeV, of a nucleus of .

nuclear mass of = 58.93320 u

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binding energy = ____________________ MeV (3)

(b) A nucleus of iron Fe-59 decays into a stable nucleus of cobalt Co-59. It decays by β– emission followed by the emission of γ-radiation as the Co-59 nucleus de-excites into its ground state.

The total energy released when the Fe-59 nucleus decays is 2.52 × 10–13 J.

The Fe-59 nucleus can decay to one of three excited states of the cobalt-59 nucleus as shown below. The energies of the excited states are shown relative to the ground state.

Calculate the maximum possible kinetic energy, in MeV, of the β– particle emitted when the Fe-59 nucleus decays into an excited state that has energy above the ground state.

maximum kinetic energy = ____________________ MeV (2)

(c) Following the production of excited states of , γ-radiation of discrete wavelengths is emitted.

State the maximum number of discrete wavelengths that could be emitted.

maximum number = ____________________

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(1)

(d) Calculate the longest wavelength of the emitted γ-radiation.

Longest wavelength = ____________________ m (3)

(Total 9 marks)

Q12. (a) (i) Define the atomic mass unit.

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(ii) State and explain how the mass of a nucleus is different from the total mass of its protons and neutrons when separated.

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(b) Explain why nuclei in a star have to be at a high temperature for fusion to take place.

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(c) (i) In massive stars, nuclei of hydrogen are processed into nuclei of

helium through a series of interactions involving carbon, nitrogen and oxygen called the CNO cycle.

Complete the nuclear equations below that represent the last two reactions in the series.

(3)

(ii) The whole series of reactions is summarised by the following equation.

Calculate the energy, in Me V, that is released.

nuclear mass of = 4.00150 u

energy ____________________ Me V (3)

(Total 12 marks)

Q13. (a) Ancient rocks can be dated by measuring the proportion of trapped argon gas to the

radioactive isotope potassium-40. Potassium-40 produces argon as a result of electron capture. The gas is trapped in the molten rock when the rock solidifies.

(i) Write down an equation to represent the process of electron capture by a potassium nucleus.

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(ii) The atomic masses of potassium-40 and argon-40 are 39.96401 u and 39.96238 u, respectively. Calculate the energy released, in MeV, when the

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process given in part (a)(i) occurs.

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(iii) An argon atom formed in this way subsequently releases an X-ray photon. Explain how this occurs.

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(b) Potassium-40 also decays by beta emission to form calcium-40.

(i) Write down an equation to represent this beta decay.

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(ii) This process is eight times more probable than electron capture. A rock sample is found to contain 1 atom of argon-40 for every 5 atoms of potassium-40. The half-life of potassium-40 is 1250 million years. Calculate the age of this rock.

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(Total 9 marks)

Q14. Deuterium ( ) and tritium ( ) nuclei will fuse together, as illustrated in the equation below.

(a) State the nucleon number and the proton number for the product of the reaction which has been written as X in the equation.

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nucleon number ____________________

proton number ____________________ (2)

(b) The masses of the particles involved in the reaction are:

mass of = 3.34250 × 10–27 kg

mass of = 5.00573 × 10–27 kg

mass of = 6.62609 × 10–27 kg

mass of neutron = 1.67438 × 10–27 kg

(i) Explain why energy is released during this reaction.

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(ii) Calculate the amount of energy released when a deuterium nucleus fuses with a tritium nucleus.

The speed of electromagnetic radiation, c = 3.0 × 108 m s–1

(3) (Total 7 marks)

Q15. A small portion of the hydrogen in air is the isotope tritium . This is continually being formed in the upper atmosphere by cosmic radiation so that the tritium content of air is constant. Tritium is a beta emitter with a half-life of 12.3 years.

(a) (i) Write down the symbols for the two isotopes of hydrogen, the atoms of which have lower masses than those of tritium.

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(ii) Write down the nuclear equation that represents the decay of tritium using the symbol X for the daughter nucleus.

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(iii) Calculate the decay constant for tritium in year–1. (1)

(b) When wine is sealed in a bottle no new tritium forms and the activity of the tritium

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content of the wine gradually decreases with time. At one time the activity of the tritium in an old bottle of wine is found to be 12% of that in a new bottle. Calculate the approximate age of the old wine.

(3)

(c)

mass of a tritium nucleus mass of a proton mass of a neutron atomic mass unit, u speed of electromagnetic radiation in free space

= 3.016050 u = 1.007277 u = 1.008665 u = 1.660566 × 10–27 kg = 3.0 × 108 m s–1

Calculate:

(i) the mass change, in kg, when a tritium nucleus is formed from its component parts,

(2)

(ii) the binding energy, in J, of a tritium nucleus. (2)

(Total 11 marks)

Q16. (a) State what is meant by the binding energy of a nucleus.

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(b) (i) When a nucleus absorbs a slow-moving neutron and undergoes fission

one possible pair of fission fragments is technetium and indium . Complete the following equation to represent this fission process.

(1)

(ii) Calculate the energy released, in MeV, when a single nucleus undergoes fission in this way.

binding energy per nucleon of = 7.59 MeV


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energy released ____________________ MeV (3)

(iii) Calculate the loss of mass when a nucleus undergoes fission in this way.

loss of mass ____________________ kg (2)

(c) (i) On the figure below sketch a graph of neutron number, N, against proton number, Z, for stable nuclei.

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proton number, Z

(1)

(ii) With reference to the figure, explain why fission fragments are unstable and explain what type of radiation they are likely to emit initially.

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(Total 12 marks)

Q17.

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(a) In the reactor at a nuclear power station, uranium nuclei undergo induced fission with thermal neutrons. Explain what is meant by each of the terms in italics.

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(b) A typical fission reaction in the reactor is represented by

(i) Calculate N.

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(ii) How do the neutrons produced by this reaction differ from the initial neutron that goes into the reaction?

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(iii) Calculate the energy released in MeV when one uranium nucleus undergoes fission in this reaction. Use the following data.

mass of neutron = 1.00867 u mass of 235U nucleus = 234.99333 u mass of 92Kr nucleus = 91.90645 u mass of 141Ba nucleus = 140.88354 u 1 u is equivalent to 931 MeV

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(Total 8 marks)

Q18. The figure below shows the variation in binding energy per nucleon with nucleon number.

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(a) A uranium-235, 235U, nucleus fissions into two approximately equally sized products. Use data from the graph to show that the energy released as a result of the fission is approximately 4 × 10–11J. Show on the graph how you have used the data.

(4)

(b) Using the data below, show that the energy available from the fusion of two hydrogen-2,2H, nuclei to make a helium-4,4He, nucleus is approximately 3.7 × 10–12 J.

mass of 2H = 2.0135 u mass of 4He = 4.0026 u

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(4)

(c) Compare the energy available from the complete fission of 1 kg of uranium-235 with the energy available from the fusion of 1 kg of hydrogen-2.

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(d) Fission and fusion reactions release different amounts of energy. Discuss other reasons why it would be preferable to use fusion rather than fission for the production of electricity, assuming that the technical problems associated with fusion could be overcome.

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(Total 13 marks)

Q19. The diagram shows how the binding energy per nucleon varies with nucleon number.

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(a) (i) Fission and fusion are two nuclear processes in which energy can be released. Explain why nuclei that undergo fission are restricted to a different part of the graph than those that undergo fusion.

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(ii) Explain, with reference to the diagram, why the energy released per nucleon from fusion is greater than that from fission.

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(b) (i) Calculate the mass difference, in kg, of the nucleus.

mass of nucleus = 15.991 u

mass difference = ____________________ kg (2)

(ii) Using your answer to part (b)(i), calculate the binding energy, in MeV, of an oxygen nucleus.

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binding energy = ____________________ MeV (1)

(iii) Explain how the binding energy of an oxygen nucleus can be calculated with information obtained from the diagram.

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(Total 8 marks)

Q20.

(a) On the axes above, sketch a graph to show how the average binding energy per nucleon depends on the nucleon number, A, for the naturally occurring nuclides. Show appropriate values for A on the horizontal axis of the graph.

(3)

(b) (i) Briefly explain what is meant by nuclear fission and by nuclear fusion.

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(ii) Describe how the graph in part (a) indicates that large amounts of energy are available from both the fission and the fusion processes.

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(Total 6 marks)

Q21. (a) Uranium-238 decays by alpha emission to thorium-234. The table shows the

masses in atomic mass units, u, of the nuclei of uranium-238 ( ), thorium-234, and an alpha particle (helium-4).

Element Nuclear mass/u

Uranium-238 238.0002

Thorium-234 233.9941

Helium-4, alpha particle 4.0015

1 atomic mass unit, u = 1.7 × 10–27 kg speed of electromagnetic radiation, c = 3.0 × 108 m s–1

the Planck constant, h = 6.6 × 10–34 J s

(i) How many neutrons are there in a uranium-238 nucleus?

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(ii) How many protons are there in a nucleus of thorium?

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(b) (i) Determine the mass change in kg when a nucleus of uranium-238 decays by alpha emission to thorium-234.

(2)

(ii) Determine the increase in kinetic energy of the system when a uranium-238 nucleus decays by alpha emission to thorium-234.

(2)

(c) Wave particle duality suggests that a moving alpha particle (mass 6.8 × 10–27 kg) has a wavelength associated with it. One alpha particle has an energy of 7.0 × 10–13 J.

Calculate:

(i) the momentum of the alpha particle; (2)

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(ii) the wavelength associated with the alpha particle. (2)

(Total 10 marks)

Q22.

Americium-241 ( Am) is a common laboratory source of alpha radiation. It decays spontaneously to neptunium (Np) with a decay constant of 4.8 × 10–11 s–1.

A school laboratory source has an activity due to the presence of americium of 3.7 × 104 Bq when purchased.

Avogadro constant = 6.0 × 1023 mol–1

one year = 3.2 × 107 s

(a) (i) Calculate the half-life, in years, of americium-241.

(2)

(ii) Calculate the number of radioactive americium atoms in the laboratory source when it was purchased.

(2)

(iii) Calculate the activity of the americium in the laboratory source 50 years after being purchased.

(3)

(iv) Suggest why the actual activity of the sources is likely to be greater than your answer to part (iii).

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(b) (i) Use the following data to deduce the energy released in the decay of one americium-241 nucleus.

mass of americium-241 nucleus = 4.00171 × 10–25 kg mass of an alpha particle = 0.06644 × 10–25 kg mass of neptunium nucleus = 3.93517 × 10–25 kg speed of electromagnetic radiation = 3.00 × 108 m s–1

in free space

(3)

(ii) Explain what is meant by decays spontaneously and how consideration of the masses of particles involved in a proposed decay helps in deciding whether the decay is possible.

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(2) (Total 13 marks)

Q23. You may be awarded marks for the quality of written communication provided in your answers to part (a)

(a) In the context of an atomic nucleus,

(i) state what is meant by binding energy, and explain how it arises,

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(ii) state what is meant by mass difference,

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(iii) state the relationship between binding energy and mass difference.

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(b) Calculate the average binding energy per nucleon, in MeV nucleon–1, of the zinc

nucleus .

mass of atom = 63.92915 u

mass of proton = 1.00728 u

mass of neutron = 1.00867 u

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mass of electron = 0.00055 u

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(c) Why would you expect the zinc nucleus to be very stable?

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(Total 10 marks)

Q24. Nuclear binding energy is

A the energy required to overcome the electrostatic force between the protons in the nucleus

B energy equivalent of the mass of the protons in the nucleus

C the energy equivalent of the mass of all the nucleons in the nucleus

D the energy equivalent of the difference between the total mass of the individual nucleons and their mass when they are contained in the nucleus

(Total 1 mark)

Q25. The reaction shown below occurs when a proton and a deuterium nucleus, H, fuse to

form a helium nucleus, He.

P + H He + Q

If the energy released, Q, is 5.49 MeV, what is the mass of the helium nucleus?

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mass of H nucleus = 2.01355 u mass of proton = 1.00728 u 1u is equivalent to 931.3 Me V

A 0.00589 u

B 3.01494 u

C 3.02083 u

D 3.02323 u (Total 1 mark)

Q26. What is the mass difference of the Li nucleus?

Use the following data: mass of a proton = 1.00728 u mass of a neutron = 1.00867 u mass of Li nucleus = 7.01436 u

A 0.93912 u

B 0.04051 u

C 0.04077 u

D 0.04216 u (Total 1 mark)

Q27. The fusion of two deuterium nuclei produces a nuclide of helium plus a neutron and liberates 3.27 MeV of energy. How does the mass of the two deuterium nuclei compare with the combined mass of the helium nucleus and neutron?

A It is 5.8 × 10−30 kg greater before fusion.

B It is 5.8 × 10−30 kg greater after fusion.

C It is 5.8 × 10−36 kg greater before fusion.

D It is 5.8 × 10−36 kg greater after fusion. (Total 1 mark)

Q28. The nuclear fuel, which provides the power output in a nuclear reactor, decreases in mass at a rate of 6.0 × 10−6 kg per hour. What is the maximum possible power output of the reactor?

A 42 kW

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B 75 MW

C 150 MW

D 300 MW (Total 1 mark)

Q29. Uranium-236 undergoes nuclear fission to produce barium-144, krypton-89 and three free neutrons.

What is the energy released in this process?

Nuclide Binding energy per nucleon / MeV

7.5

8.3

8.6

A 84 MeV

B 106 MeV

C 191 MeV

D 3730 MeV (Total 1 mark)

Q30. What is the binding energy of the nucleus U?

Use the following data:

mass of a proton =1.00728 u

mass of a neutron = 1.00867 u

mass of a U nucleus = 238.05076 u

1 u = 931.3 MeV

A 1685 MeV

B 1732 MeV

C 1755 MeV

D 1802 MeV (Total 1 mark)

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Q31. The mass of the nuclear fuel in a nuclear reactor decreases at a rate of 1.2 × 10−5 kg per hour. Assuming 100% efficiency in the reactor what is the power output of the reactor?

A 100 MW

B 150 MW

C 200 MW


Q32.

The mass of the beryllium nucleus, Be , is 7.01473 u. What is the binding energy per nucleon of this nucleus?

Use the following data:

mass of proton = 1.00728 u mass of neutron = 1.00867 u 1u = 931.3 MeV

A 1.6 MeV nucleon−1

B 5.4 MeV nucleon−1

C 9.4 MeV nucleon−1

D 12.5 MeV nucleon−1

(Total 1 mark)

Q33. The power output of a nuclear reactor is provided by nuclear fuel which decreases in mass at a rate of 4.0 × 10−6 kg hour−1.

What is the maximum possible power output of the reactor?

A 28 kW

B 50 MW

C 100 MW


Q34. In the reaction shown, a proton and a deuterium nucleus, , fuse together to form a

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helium nucleus,

What is the value of Q, the energy released in this reaction?

mass of a proton = 1.00728 u

mass of a nucleus = 2.01355 u

mass of a nucleus = 3.01493 u

A 5.0 MeV

B 5.5 MeV

C 6.0 MeV

D 6.5 MeV (Total 1 mark)

Q35. The graph shows how the binding energy per nucleon varies with the nucleon number for stable nuclei.

What is the approximate total binding energy for a nucleus of ?

A 1.28 pJ

B 94.7 pJ

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C 103 pJ

D 230 pJ

(Total 1 mark)

8.6 Nuclear Physics - Mass and Energy - Qs

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Transcript of 8.6 Nuclear Physics - Mass and Energy - Qs