AQA GCSE Physics 27 Nuclear Physics

1
AQA GCSE Physics 2-7Nuclear Physics

• GCSE Physics pages 198 to 209

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AQA GCSE Specification

• NUCLEAR DECAY
• 12.9 What happens to radioactive substances
• when they decay?
• Using skills, knowledge and understanding of how
  science works
• to explain how the Rutherford and Marsden
  scattering experiment led to the .plum pudding.
  model of the atom being replaced by the nuclear
  model.
• Skills, knowledge and understanding of how
  science works set in the context of
• The relative masses and relative electric
  charges of protons, neutrons and electrons.
• In an atom the number of electrons is equal to
  the number of protons in the nucleus. The atom
  has no net electrical charge.
• Atoms may lose or gain electrons to form
  charged particles called ions.
• All atoms of a particular element have the
  same number of protons.
• Atoms of different elements have different
  numbers of protons.
• Atoms of the same element which have different
  numbers of neutrons are called isotopes.
• The total number of protons and neutrons in an
  atom is called its mass number.
• The effect of alpha and beta decay on
  radioactive nuclei.
• The origins of background radiation.

• NUCLEAR FISSION FUSION
• 12.10 What are nuclear fission and nuclear
  fusion?
• Using skills, knowledge and understanding of how
  science works
• to sketch a labelled diagram to illustrate how
  a chain reaction may occur.
• Skills, knowledge and understanding of how
  science works set in the context of
• There are two fissionable substances in common
  use in nuclear reactors, uranium 235 and
  plutonium 239.
• Nuclear fission is the splitting of an atomic
  nucleus.
• For fission to occur the uranium 235 or
  plutonium 239 nucleus must first absorb a
  neutron.
• The nucleus undergoing fission splits into two
  smaller nuclei and 2 or 3 neutrons and energy is
  released.
• The neutrons may go on to start a chain
  reaction.
• Nuclear fusion is the joining of two atomic
  nuclei to form a larger one.
• Nuclear fusion is the process by which energy
  is released in stars.

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Nuclear reactionsNotes questions from pages 198
199

• Copy the table near the top of page 198.
• Define what is meant by (a) an ion (b) atomic
  number (c) mass number (d) isotopes.
• Copy all parts of Figure 1 on page 198.
• Copy and answer question (a) on page 198.
• By giving an example equation in each case
  describe the processes of (a) alpha decay and
  (b) beta decay.
• Compare gamma emission with alpha and beta decay.
• Copy and answer questions (b) and (c) on page
  199.
• What is background radiation? Copy the pie chart
  on page 199.
• Copy the Key points table on page 199.
• Answer the summary questions on page 199.

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Nuclear reactions ANSWERS

• In text questions
• 92p, 143n
• 23890Th 90p 138n 22488Ra 88p 136n
• 4019K 19p 21n 4020Ca 20p 20n

• Summary questions
• (a) 6p 6n
• (b) 27p 33n
• (c) 92p 143n
• (a) 92p 146n
• (b) 90p 144n
• (c) 91p 143n

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The discovery of the nucleusNotes questions from
pages 200 201

• (a) With a copy made of Figure 1 describe the
  experiment performed by Hans Geiger and Ernest
  Marsden that supported Rutherfords model of the
  atom. (b) What were the results of the above
  experiment? (c) Explain how these results
  supported Rutherfords model. Draw Figure 2 on
  page 201 as part of your answer.
• What was the plum pudding model?
• Copy and answer questions (a) and (b) on pages
  200 and 201.
• Copy the Key Points on page 201.
• Answer the summary questions on page 201.

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The discovery of the nucleus ANSWERS

• In text questions
• It had to hit something much heavier.
• Rutherfords model would have been incorrect.

• Summary questions
• (a) Charge
• (b) Diameter
• (c) Mass
• 2. (a) Path B
• (b) A is wrong because it is attracted by
  the nucleus C is wrong because it is unaffected
  by the nucleus D is wrong because it is repelled
  by the nucleus through too great an angle.

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Nuclear fission Notes questions from pages 202
203

• Define what is meant by nuclear fission.
• With aid of a copy of Figure 1, explain what is
  meant by a chain reaction.
• Explain the purpose of fission neutrons in a
  chain reaction.
• Copy and answer question (a) on page 202.
• What isotopes are used for fission reactions?
• Copy Figure 3 on page 203 explain how a nuclear
  fission reactor produces steam to drive the
  turbines of a power station. Your account should
  include the purpose of the moderator, control
  rods and coolant.
• Copy and answer question (b) on page 203.
• Copy the Key Points on page 203.
• Answer the summary questions on page 203.

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Nuclear fission ANSWERS

• In text questions
• The chain reaction would go out of control and
  the reactor would explode.
• The chain reaction would go out of control and
  the reactor would explode.

• Summary questions
• (a) Nucleus,
• uranium-235, plutonium-239.
• (b) Uranium-238, plutonium-239.
• 2. 1A, 2C, 3B, 4A

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Nuclear fusionNotes questions from pages 204
205

• Explain what is meant by nuclear fusion.
• Outline the fusion reactions that take place
  inside the Sun.
• What would be the advantages of using a nuclear
  fusion reactor over other methods of generating
  electricity?
• Copy and answer questions (a) and (b) on pages
  204 and 205.
• Copy the Key Points on page 205.
• Answer the summary questions on page 205.

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Nuclear fusion ANSWERS

• In text questions
• Helium-3 nucleus
• It goes out of control, the plasma would touch
  the walls and go cold.

• Summary questions
• 1. (a) Small, larger (b) Stable
• 2. (a) So the nuclei have enough kinetic energy
  to overcome the force of repulsion between them
  and fuse.
• (b) The energy output would be less than the
  energy input so it would not produce any energy
  overall.

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Nuclear energy issuesNotes questions from pages
206 207

• No questions

12
How Science Works ANSWERS

• Random error. The differences show no pattern and
  radioactive decay is a random process.
• The background radiation levels stay more or less
  constant in these time scales and so will affect
  each reading equally.
• It must be used sensibly and stored safely to
  ensure that as little as possible gets into the
  enviroment.
• Examples
• (i) What did the people die from?
• (ii) How many people were in the survey?
• (iii) Do all prostate cancer patients get this
  treatment?
• (iv) Was there a control group?
• (v) How many would have died anyway?