IB Physics SL E 4 Fission Questions
Practise IB Physics SL E.4 by balancing fission equations, interpreting binding energy and evaluating chain-reaction evidence.
- Syllabus
- First assessment 2025
- Course
- Physics SL
- Level
- SL
Exam points
- balance and interpret nuclear fission equations, identifying emitted particles, nucleon conservation and energy release
- calculate or interpret mass defect, binding energy and specific energy released in fission
- explain chain reactions and the roles of moderators, control rods, heat exchangers and safety measures using reactor evidence
Covered syllabus points
Question 1
[Maximum number: 6]
This question is in two parts. Part 1 is about energy resources. Part 2 is about thermal physics.
Part 1 Energy resources
Electricity can be generated using nuclear fission, by burning fossil fuels or using pump storage hydroelectric schemes.
Question (a)
(a)
In a nuclear reactor, outline the purpose of the
Question (i)
(i)
heat exchanger.
(allows coolant to) transfer thermal/heat (energy) from the reactor/(nuclear) reaction to the water/steam;
Must see reference to transfer.
Question (ii)
(ii)
moderator.
reduces speed/kinetic energy of neutrons;
(do not allow "particles") improves likelihood of fission occurring/U-235 capturing neutrons;
Question (b)
(b)
Fission of one uranium-235 nucleus releases 203 MeV .
Question (i)
(i)
Determine the maximum amount of energy, in joule, released by 1.0 g of uranium-235 as a result of fission.
( 203 MeV is equivalent to) 3.25×10−11 J;
6.02×1023 nuclei have a mass of 235 g/ evaluates number of nuclei;
( 2.56×1021 nuclei produce) 8.32×1010 J/ multiplies two previous answers;
Question 2
[Maximum number: 3]
This question is about nuclear power production.
Outline the reason why fuel enrichment is necessary for the fuel used in a commercial nuclear reactor.
U-235 is (much) more fissionable than U-238 / U-238 is a good absorber of neutrons / U-238 removes neutrons from the reaction / U-238 cannot produce a chain/sustainable reaction;
(naturally occurring) uranium (ore) contains more U-238 (atoms) than U-235 (atoms) / very little U-235 in ore;
in fuel enrichment, U-238 is removed / the percentage of U-235 is increased / the ratio of U-235 to U-238 is increased / amount of U-235 increases;
Question 3
[Maximum number: 3]
This question is about energy sources.
A small island is situated in the Arctic. The islanders require an electricity supply but have no fossil fuels on the island. It is suggested that wind generators should be used in combination with power stations using either oil or nuclear fuel.
A nuclear reactor requires both control rods and a moderator to operate. Outline, with reference to neutrons, one similarity and two differences in the function of each of these components.
control rods absorb neutrons;
moderators slow down neutrons;
both affect the rate of reaction;
both rely on the neutrons colliding with their atoms/nuclei;
Must see reference to collision/interaction for fourth marking point.
Question 4
[Maximum number: 3]
This question is in two parts. Part 1 is about energy resources. Part 2 is about thermal physics.
Part 1 Energy resources
Electricity can be generated using nuclear fission, by burning fossil fuels or using pump storage hydroelectric schemes.
Fission of one uranium-235 nucleus releases 203 MeV .
Determine the maximum amount of energy, in joule, released by 1.0 g of uranium-235 as a result of fission.
( 203 MeV is equivalent to) 3.25×10−11 J;
6.02×1023 nuclei have a mass of 235 g/ evaluates number of nuclei;
( 2.56×1021 nuclei produce) 8.32×1010 J/ multiplies two previous answers;
Question 5
[Maximum number: 1]
In nuclear power production, what is one advantage of a nuclear fusion reactor over a nuclear fission reactor?
A
The operating temperature of the fusion reactor is lower.
B
The nuclear reactants are more easily confined within the core of the fusion reactor.
C
The disposal of the nuclear waste products from the fusion reactor is more straightforward.
D
The nuclear fusion reaction is more easily sustained for long periods of time.
C
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