Nuclear Fission & Fusion (Edexcel GCSE Physics)

Exam Questions

2 hours12 questions
1a
Sme Calculator
2 marks

Radioactive substances are used in the generation of electricity.
State two other uses of radioactive substances.

1b
Sme Calculator
2 marks

Figure 1 is a diagram of a nuclear reactor, used in the generation of electricity.

fig-1-paper1h-june2020-edexcel-gcse-physics

Figure 1

P may be used to shut down the reactor when necessary.
Q slows down neutrons to enable a chain reaction to take place.

State the name of the two parts labelled P and Q.

P ..........................................................
Q ..........................................................

1c
Sme Calculator
2 marks

Explain how neutrons enable a nuclear chain reaction to take place.

Did this page help you?

2a1 mark

The element which undergoes fission in a nuclear reactor is

square   A   hydrogen-1

square   B   helium-4

square   C   uranium-235

square   D   radium-226

    2b
    Sme Calculator
    1 mark

    The particle released during fission which can initiate a chain reaction is 

    square   A   a nucleon

    square   B   a neutron

    square   C   an alpha particle

    square   D   a beta particle

      2c
      Sme Calculator
      4 marks

      The following passage is about control rods and moderators in a nuclear reactor. Select words from the box to complete the sentences.

        

      graphite ionise refract magnesium
      boron slow cardboard absorb

        

      The moderator in a nuclear reactor is often made from ..............................

      The moderator is used to .............................. neutrons.

      The control rods in a nuclear reactor are often made from ..............................

      The control rods are used to .............................. neutrons.

      2d
      Sme Calculator
      2 marks

      This question is about the differences between nuclear fission and fusion.

      Place a tick (✔) next to the correct statements

      Fission is the splitting of a large nucleus into daughter nuclei  
      Electrons are released alongside the daughter nuclei in fission  
      Fusion is the joining of two smaller nuclei into a heavier nucleus  
      Fission releases energy, but fusion does not  

      Did this page help you?

      3a
      Sme Calculator
      1 mark

      Nuclear fusion is defined as

      square   A   the creation of a larger nucleus from smaller nuclei

      square   B   the emission of an electron from the nucleus

      square   C   the cooling of the Sun

      square   D   a natural process which occurs in the core of the Earth

        3b
        Sme Calculator
        1 mark

        An element that might undergo fusion is

        square   A   polonium-210

        square   B   americium-241

        square   C   uranium-235

        square   D   hydrogen-1

          3c
          Sme Calculator
          1 mark

          Which of the following are the correct conditions for nuclear fusion to occur?

          square   A   low temperature, low pressure

          square   B   low temperature, high pressure

          square   C   high temperature, low pressure

          square   D   high temperature, high pressure

            3d1 mark

            State why the conditions you chose in (c) are necessary for fusion to take place.

            Did this page help you?

            4a
            Sme Calculator
            1 mark

            Nuclear fission is defined as

            square   A   the process of transforming mercury into gold

            square   B   a process which does not produce radioactive waste material

            square   C   the splitting of a larger nucleus into two smaller nuclei

            square   D   a process which takes in more energy than it releases

              4b
              Sme Calculator
              3 marks

              The following passage describes some of the properties of fission.

              Use words from the box to complete the passage.

                

              shielding fast high
              fuel rods daughter baby

                

              The .............................. nuclei produced in nuclear fission are highly radioactive.

              They emit .............................. energy neutrons when they decay.

              Concrete .............................. can be used to absorb the neutrons.

              4c
              Sme Calculator
              4 marks

              The following passage is about chain reactions.

              Use words from the box to complete the following sentences.

              Each word can be used once, more than once or not at all.

                

              uranium fission neutrons two three

                

              One nucleus of ............................. undergoes fission to form ............................. daughter nuclei

              ............................. are released alongside the daughter nuclei

              The ............................. released by fission are absorbed by other ............................. nuclei

              This causes the ............................. of these ............................. nuclei

              Did this page help you?

              1a6 marks

              Fusion and fission are nuclear reactions in which large amounts of energy are released.

              i)
              In a fusion reaction, two hydrogen nuclei are forced together to form a helium nucleus.

              Explain why a very high temperature is needed for this reaction to happen.
              [3]

              ii)
              In a fusion reaction, the combined mass of the two small nuclei is greater than the mass of the resulting nucleus.

              This decrease in mass, m, appears as energy, E, according to the equation.

              E = mc2

              c is the speed of light = 3.0 × 108 m/s.

              The energy released in one fusion reaction is 4.5 × 10−12 J.

              Calculate the decrease in mass.

              [3]

                       decrease in mass = .............................................................. kg

              1b6 marks

              Nuclear fission is used in nuclear reactors in some power stations.

              In the reactor, a fission chain reaction is maintained and controlled to produce a supply of energy to generate electricity.


              Figure 14 is a diagram of a nuclear reactor.

              fig-14-ipho-1h-june18-qp-edexcel-gcse-physics
              Figure 14

              Explain how the graphite core and the movable rods are used to maintain and control the chain reaction.

              Did this page help you?

              2a1 mark

              This question is about nuclear reactions.

              When a uranium-235 (U-235) nucleus absorbs a neutron, the nucleus splits into smaller parts.

              This reaction is called nuclear fission.

              How many daughter nuclei are produced from the fission of one nucleus of uranium-235 (U-235)?

                A two
                B three
                C four
                D six
              2b6 marks
              i)
              When a uranium-235 (U-235) nucleus splits, neutrons are also emitted.

              The neutrons may start a chain reaction.

              Describe what is meant by a chain reaction.

              You may draw a diagram to help with your answer.

              [2]

              ii)
              In the nuclear reactor of a power station, the chain reaction has to be controlled.

              Explain the action of a moderator in a nuclear reactor.

              [2]

              iii)
              In a nuclear reactor there are 2.0 × 1017 fission reactions each second.

              Each fission reaction releases 4.0 × 10–11 J of energy.

              Calculate the energy released in 1 second.

              [2]

              energy released in 1 second = .............................................................. J

              2c2 marks

              Nuclear fusion is a nuclear reaction that takes place in the Sun.

              Describe what happens during a nuclear fusion reaction.

              Did this page help you?

              3a1 mark

              Figure 8 shows a helium nucleus.

              fig8-paper1f-june2018-edexcel-gcse-physics

              Figure 8

              Two of the particles in the helium nucleus are neutrons.

              State the name of the other two particles in the helium nucleus.

              3b3 marks
              i)
              Describe the difference between a fusion reaction and a fission reaction.

              [2]

              ii)
              Nuclear fusion does not happen at low temperatures because of electrostatic repulsion between
              [1]
                A beta particles
                B electrons
                C neutrons
                D protons
              3c6 marks

              The energy released per kilogram of fuel in a fusion reaction is 845 000 GJ.

              The energy released per kilogram of fuel in burning oil is 0.0394 GJ.

              i)
              Calculate the ratio of the energy released in fusion compared with the energy released in burning oil.

              Use the equation
              ratio equals fraction numerator energy space released space from space fusion over denominator energy space released space by space burning space oil end fraction

              [2]

              ratio = ..............................................................

              ii)
              State two advantages of using a fusion reactor rather than burning oil in a power station.

              [2]

              1..................................................................

              2...................................................................

              iii)
              State two of the difficulties that need to be overcome to produce a fusion reactor.
              [2]
              1.................................................................

              2.................................................................

              Did this page help you?

              4a4 marks
              Figure 1 shows the main parts of a nuclear reactor.

              6-4-m-4a-nuclear-fission-reactor

              Figure 1

              State the function of:
               
              (i)
              The control rods
              [1]
              (ii)
              The coolant
              [1]
              (iii)
              The fuel rods
              [1]
              (iv)
              The shielding
              [1]
              4b1 mark

              The uranium fuel has a nuclear energy store.

              State the name of the energy store that energy is usefully transferred to during a fission reaction.

              4c2 marks

              Explain the role of the moderator in a fission reactor.

              4d3 marks

              Explain what is meant by controlled nuclear fission.

              Refer to neutrons in your answer.

              Did this page help you?

              5a5 marks

              Nuclear fission occurs in nuclear reactors.

              Describe the process of nuclear fission, including the material used in the fuel rod.

              Explain what happens to the energy released. 

              5b4 marks

              Explain how a chain reaction can occur in the reactor.

              5c2 marks

              Scientists in France are currently developing a nuclear fusion reactor called ITER for research into fusion technology.

              Nuclear fusion uses isotopes of hydrogen called deuterium and tritium.

              Deuterium can be reasonably easily extracted from seawater, and is naturally occurring.

              Table 1 below shows the energy released from 1kg of deuterium and 1kg of uranium-235 used as the fuel in a fission power station.

              Type of fuel

              Energy released from 1kg of fuel (J)

              Deuterium

              2.4 x 1014

              Uranium-235

              8.7 x 1013

               Table 1

              Suggest two advantages of using a nuclear fusion reactor rather than a nuclear fission reactor.

              5d2 marks

              State and explain the conditions for nuclear fusion to occur.

              Did this page help you?

              1a3 marks

              Use words from the box to complete the sentences about nuclear fission of uranium‐235 (U‐235).

              chain chemical fuse
              neutrons protons split

              A neutron hits a nucleus of U‐235 and causes the nucleus to ......................................

              Each fission releases energy, two daughter nuclei and some ....................................... .

              In a nuclear reactor, one fission can set off a controlled ............................... reaction.
              1b2 marks

              Both U‐235 and oil can be used as energy sources for generating electricity.

              1 kg of natural uranium can result in the generation of 45 000 units of electricity.

              1 kg of oil can result in the generation of 5.0 units of electricity.

              Calculate the mass of oil needed to generate the same amount of electricity as 1 kg of natural uranium.

              mass of oil = .............................................................. kg

              1c2 marks

              Both using nuclear fuel and burning oil produce harmful waste products.

              State one harmful waste product from each process.


              using nuclear fuel...................................................................

              burning oil...............................................................................

              1d6 marks
              Figure 14 shows a household smoke alarm that uses radioactivity to detect smoke.

              fig-14-paper1f-june2020-edexcel-gcse-physics
              Figure 14

              The radioactive source in the smoke detector is americium–241.

              The table in Figure 15 shows some information about americium–241 and two other radioactive sources.

              radioactive source type of radiation half‐life
              americium–241 alpha 433 years
              actinium‐225 alpha 10 days
              cobalt‐60 gamma 5.27 years

              Figure 15

              Explain why americium‐241 is the best of these three sources to use in this smoke detector.

              Use information from Figure 15 and your own knowledge about radiation.

              Your answer should refer to

              • properties of alpha and gamma radiation
              • half‐life.

              Did this page help you?

              2a3 marks

              A kettle is used to heat water.

              Figure 11 shows a graph of temperature against time for the water in the kettle.

               h1-q8a

              Calculate the rate of increase in temperature at a time of 150 s, by drawing a tangent to the curve in Figure 11 at a time of 150s.

              .............................................................. °C/s

              2b2 marks

              The kettle has an efficiency of 91% in supplying energy to the water.
              The thermal energy of the water increases by 3.3 × 105 J in 200 s.

              Calculate the total amount of energy supplied to the kettle in the 200 s.
              Use the equation

              efficiency space equals space fraction numerator left parenthesis useful space energy space transferred space by space the space device right parenthesis over denominator left parenthesis total space energy space supplied space to space the space device right parenthesis end fraction


              total amount of energy supplied = .............................................................. J

              2c6 marks
              c)
              The global demand for electricity is increasing.
              There is a debate about whether nuclear power generation should or should not contribute to meeting this increasing demand.


              Discuss the arguments for and against using nuclear power to meet the increasing global demand for electricity.

              (6)

              Did this page help you?

              3a
              Sme Calculator
              5 marks

              Nuclear fission occurs in nuclear reactors.

              An example of a nuclear reactor is shown in Figure 1.

               
              4-4-h-1a-nuclear-reactor
              Figure 1

               

              Describe the process of nuclear fission in the reactor shown in Figure 1, including the material used in the fuel rod.

              Explain what happens to the energy released. 

              3b
              Sme Calculator
              4 marks

              Explain how a chain reaction can occur in the reactor.

              3c
              Sme Calculator
              2 marks

              Explain the energy transfer taking place in this chain reaction.

              Did this page help you?