IGCSEPhysicsEdexcelExam Questions7. Radioactivity & ParticlesFission & Fusion

Fission & Fusion (Edexcel IGCSE Physics)

Exam Questions

2 hours15 questions
Easy
Medium
Hard
11 mark

The diagram shows a nuclear reactor.

7-3-mcqs-q1-question

A uranium nucleus in the fuel rod may split when a neutron hits it.

This process of splitting is known as ...

  • fission

  • moderation

  • reflection

  • refraction

Choose your answer

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2a4 marks

The diagram shows a nuclear reactor.

7-3-mcqs-q1-question

Match each part of the reactor to its function:

7-3-easy-q2a-parts-of-a-nuclear-reactor

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2b3 marks

The sentences relate to nuclear fission and fusion. 

Use words from the box to complete the passage.

Sun Moon splitting

moderator fusion joining

(i) Fission is the ............... of a nucleus

(ii) Fusion is the ............... of two nucleii

(iii) Fusion occurs naturally in the ............... 

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2c2 marks

State two conditions needed for nuclear fusion.

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3a1 mark

Nuclear fission is defined as

  • the process of transmuting mercury into gold

  • a process which does not produce radioactive waste material

  • the splitting of a larger nucleus into two smaller nuclei

  • a process which takes in more energy than it releases

Choose your answer

3b3 marks

The passage describes some of the properties of fission. 

Use words from the box to complete the passage.

shielding fast high

fuel rods daughter baby

Some of the ............... nuclei produced in nuclear fission are highly radioactive and emit ............... energy neutrons when they decay. Concrete ............... can be used to absorb the neutrons.

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3c1 mark

Nuclear fusion is defined as

  • the creation of a larger nucleus from smaller nuclei

  • the emission of an electron from the nucleus

  • the cooling of the Sun

  • a natural process which occurs in the core of the Earth

Choose your answer

3d1 mark

An example of an element that might undergo fusion is

  • polonium-210

  • hydrogen-1

  • americium-241

  • krypton-84

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4a1 mark

State the most commonly used isotope which undergoes fission in a nuclear reactor.

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4b1 mark

State the particle released during fission of this substance which can enable further fission reactions.

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4c4 marks

The following passage is about chain reactions. 

Arrange the sentences into the correct order by numbering them 1 to 4.

This causes fission of these uranium nuclei

A nucleus of uranium undergoes fission to form two daughter nuclei

The neutrons released by fission are absorbed by other uranium nuclei

Neutrons are released alongside the daughter nuclei

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5a4 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. 

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5b2 marks

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

Tick the correct statements in the table below

7-3-easy-q5b-fission-and-fusion

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5c1 mark

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

  • low temperature and low pressure

  • low temperature and high volume

  • high temperature and low volume

  • high temperature and high pressure

Choose your answer

5d1 mark

State why specific conditions are required for nuclear fusion to take place.

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11 mark

The control rods control the reaction in a nuclear reactor by

  • Absorbing some of the neutrons

  • Cooling the reactor vessel

  • Removing uranium nuclei from the reaction

  • Slowing the neutrons slightly

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2a2 marks

The diagram shows the main parts of a nuclear reactor.

fission-and-fusion-sqs-q1-question

Draw a line linking each part of the reactor with its main function.

The first one has been done for you. 

j2E2WGM__fission-and-fusion-sqs-q1-question-diagram-2

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2b1 mark

In a fission reaction, energy is transferred from the nuclear store of the particles to which store?

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2c2 marks

Explain the role of the moderator in a fission reaction.

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2d3 marks

Explain, in terms of neutrons, what is meant by controlled nuclear fission. 

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3a3 marks

A student finds this representation of nuclear fission on a website.

fission-and-fusion-sqs-q2a-question

Describe what happens when nuclear fission of uranium occurs. 

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3b1 mark

The daughter nuclei move off with high speed.

Name the energy store that gives them high speed.

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4a5 marks

The diagram shows the main parts of a nuclear reactor. 

In the nuclear reactor uranium−235 nuclei undergo fission in a controlled chain reaction.

fission-and-fusion-sqs-q3a-question

Describe nuclear fission and how the chain reaction is controlled.

Use terms from the diagram to help you.

How did you do?

4b1 mark

Name the energy store that is filled after the nucleus splits in a fission reaction.

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4c1 mark

How does the shielding improve safety?

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5a2 marks

 In a nuclear reactor, a uranium-235 nucleus absorbs a neutron and fission occurs.

Complete the equation below that shows a typical fission reaction.

7-1-sqs-q6a-question

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5b3 marks

Explain how nuclear fission can lead to a chain reaction.

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5c4 marks

The diagram shows a nuclear reactor.

7-1-sqs-q6c-question

(i) On the diagram, label the control rods and the shielding.

(ii) Explain why the shielding is needed.

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1a5 marks

The diagram shows the fuel used in some nuclear reactors.

The fuel is contained inside spheres.

The silicon carbide layer of each sphere is designed to contain the fission products for at least one million years.

fission-and-fusion-sqs-q4-question

(i) Give the name of a fuel that could be used.

(ii) Explain what is meant by the term fission products.

(iii) Explain why it is important to contain these fission products for such a long time.

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1b3 marks

The graphite layer in every fuel sphere acts as a moderator.

(i) State the function of the moderator in a nuclear reactor.

(ii) The nuclear reactor also contains boron control rods.

Explain why it is dangerous to remove most of the control rods from the reactor.

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2a1 mark

The diagram shows a neutron colliding with a nucleus of uranium-235, producing a number of products.

13-3-5a

Name the process shown in the diagram.

How did you do?

2b3 marks

Explain how the process shown in the diagram can lead to a chain reaction.

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2c2 marks

This process releases energy.

Explain the energy transfer taking place in this reaction.

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2d5 marks

The energy released in this process can be used in a nuclear power station.

13-3-5d

(i) The pressurised water acts as a coolant. It also acts as a moderator.

What is the purpose of a moderator?

(ii) Complete the chart below to show the main useful energy transfers in a nuclear power station.

EV4N6xfX_13-3-5dii

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3a5 marks

Nuclear power stations use a uranium isotope as fuel. 

The table shows information about three isotopes of uranium. 

Isotope

Proton number

Neutron number

Half-life

Amount in natural uranium

Uranium-234

92

142

0.0002 billion years

0.005%

Uranium-235

143

0.7 billion years

0.7%

Uranium-238

92

4.5 billion years

99%

(i) Complete the table by filling in the missing numbers. 

(ii) Explain what is meant by the term half-life. 

(iii) Suggest why uranium-238 is the most common isotope of uranium.

How did you do?

3b3 marks

What are the products of the fission of uranium nuclei?

How did you do?

3c3 marks

The diagram shows the reactor in a nuclear power station. 

7-3-q7c-question

(i) What is the purpose of the moderator? 

(ii) Describe what happens in the reactor when a control rod is removed.  

How did you do?

3d5 marks

There have been several accidents at nuclear power stations. The most serious accident caused an explosion in the reactor. This explosion spread material from inside the reactor to the surrounding area.

Explain why it is difficult to make the surrounding area safe again after a serious nuclear accident. 

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4a5 marks

Nuclear fission occurs in nuclear reactors.

 

7-3-mcqs-q1-question

 

Describe the process of nuclear fission in the reactor, including the material used in the fuel rod. Explain what happens to the energy released.

How did you do?

4b6 marks

Explain the role of the moderator and the control rods. Suggest materials which would be suitable to use for each one.

How did you do?

4c4 marks

Explain how a chain reaction can occur in the reactor.

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5a1 mark

Which of the following statements about nuclear power is incorrect? 

  • An advantage of nuclear power is that it produces no carbon dioxide

  • Concrete shielding is a helps ensure harmful radiation does not escape from a nuclear reactor

  • The products of fusion include daughter nuclei and neutrons

  • The moderator slows down neutrons

Choose your answer

5b1 mark

Which of the following statements about nuclear fusion is incorrect?

  • Fusion requires high temperature and pressure

  • The rate of reaction of fusion can be increased using neutrons

  • Fusion occurs in the Sun

  • Fusion involves light nuclei

Choose your answer

5c1 mark

Energy and mass can be converted using the equation: 

c h a n g e space i n space e n e r g y equals c h a n g e space i n space m a s s cross times s p e e d space o f space l i g h t squared

straight capital delta E equals straight capital delta m c squared

Fusion and fission are examples of when this conversion process occurs.

A particular fusion reaction that can occur is:

7-3-hard-q5c-fusion

In this reaction:

  • Mass of reactants mR = mass of helium−3 + mass of helium−4

  • Mass of product mP = mass of beryllium−7

  • Energy is released

State and explain which quantity is greater, mR or mP.

How did you do?

5d3 marks

The difference in mass of the reactants and products was found to be 2.8 × 10–30 kg.

The speed of light is 3.00 × 108 m/s.

Calculate the amount of energy released. Give the unit.

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