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7.2. Nuclear Reactions

We learnt at GCSE that some isotopes of different elements are radioactive, Carbon-14, Uranium-235 etc. Why do some elements have halflives on the order of millions of years, whereas some decay withing milliseconds? We know that the nucleus is held together by the strong nuclear force, and the nucleon composition (numbers of protons and neutrons) of the nucleus determines the stability of these nuclei. This section looks a little bit into these ideas, and how we can calculate energy released through fission or fusion using Einstein's famous equation, E = mc².

Before we start, I love this video by Veritasium - trying to answer the question of 'What is the most radioactive place on Earth?'.

The section has been divided up as follows:

 

Nuclear Stability

We already know some nuclei are stable and some are unstable. We also know that depending on the composition of the nucleus, the nucleus may decay through alpha, beta or gamma emission. Here we explore a little bit into these ideas. Crash Course have a nice little intro to get us started.

Video Lessons

Resources

IB Physics
Topic 7 Notes
IB-Physics.net
Chapter 7 Summary
IB Revision Notes
Mr. G
7.2 Teaching Notes
7.2 Student Notes
Physics and Maths Tutor
Particles Definitions
Particles Key Points
Particles Detailed Notes
Particles Flashcards
A Level Resources - content slightly different

Questions

Cambridge University Press
Topic 7: Add Qs
Topic 7: Add Qs MS
Topic 7: MCQs
CUP Website Link
Freely available online
Grade Gorilla
7.2 (Nuclear Equations) MCQ
Topic 7 (Nuclear) End Quiz
Quick IB Specific Mixed MCQs
Mr. G
7.2 Formative Assessment
Topic 7 Summary Qs
IB Specific Questions
 

Binding Energy and Mass Defect

The key points of this section are explained quite nicely here:

This section is all about getting your head around the idea of a nuclear binding energy - the energy given out when a nucleus forms. Due to Einstein's famous equation, E=mc², this means that a bound nucleus of, for example, Helium (made of 2 protons, 2 neutrons) has a smaller mass than those same nucleons if they were free. 

The reason this is idea of binding energy is significant is because it allows us to understand how we may produce energy from nuclear fusion (the fusing of smaller nuclei to form a larger nucleus) and nuclear fission (the splitting of a large nucleus to form daughter nuclei).

It is important that we are able to understand the following plot, and the significance of Fe-56. 

Binding_energy_curve_-_common_isotopes.j

Heading 2

Fe-56 has the highest binding energy per nucleon.

To the left of Fe-56, fusion is able to occur to release energy. To the right, fission will release energy.

Video Lessons

Chris Doner
Nuclear Binding Energy
IB Specific
Gradepod
Binding Energy per Nucleon
IB Specific
Khan Academy
Mass Defect/ Binding Energy
Science Shorts
Binding Energy
Study Nova
Binding Energy
Per Nucleon

Resources

IB Physics
Topic 7 Notes
IB-Physics.net
Chapter 7 Summary
IB Revision Notes
Mr. G
7.2 Teaching Notes
7.2 Student Notes
Physics and Maths Tutor
Particles Definitions
Particles Key Points
Particles Detailed Notes
Particles Flashcards
A Level Resources - content slightly different

Questions

Cambridge University Press
Topic 7: Add Qs
Topic 7: Add Qs MS
Topic 7: MCQs
CUP Website Link
Freely available online
Dr French's Eclecticon
Nuclear Physics
Nuclear Physics Solutions
Link to Dr French's Site
Extension: Pre-University Material
Grade Gorilla
7.2 (Nuclear Equations) MCQ
Topic 7 (Nuclear) End Quiz
Quick IB Specific Mixed MCQs
Isaac Physics
Energy in Nuclear Reactions
Mr. G
7.2 Formative Assessment
Topic 7 Summary Qs
IB Specific Questions
 

Fission and Fusion

In this section, you should be able to link the above ideas of mass defect to calculate the energy produced through fission and fusion.

However, it is worth refreshing your memory on the key aspects of fission and fusion, so flick through the following resources.

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PHET have a neat simulation looking at Uranium fission and the nuclear chain reaction.

PhD Comics have a nice YouTube video discussing fusion energy

Video Lessons

Chris Doner
Fission and Fusion
IB Specific
Science Shorts
Fission and Fusion

Resources

IB Physics
Topic 7 Notes
IB-Physics.net
Chapter 7 Summary
IB Revision Notes
Mr. G
7.2 Teaching Notes
7.2 Student Notes
Physics and Maths Tutor
Particles Definitions
Particles Key Points
Particles Detailed Notes
Particles Flashcards
A Level Resources - content slightly different

Questions

Cambridge University Press
Topic 7: Add Qs
Topic 7: Add Qs MS
Topic 7: MCQs
CUP Website Link
Freely available online
Dr French's Eclecticon
Nuclear Physics
Nuclear Physics Solutions
Link to Dr French's Site
Extension: Pre-University Material
Grade Gorilla
7.2 (Nuclear Equations) MCQ
Topic 7 (Nuclear) End Quiz
Quick IB Specific Mixed MCQs
Mr. G
7.2 Formative Assessment
Topic 7 Summary Qs
IB Specific Questions
 

Additional Resources

IB Questions

A question by question breakdown of the IB papers by year is shown below to allow you to filter questions by topic. Hopefully you have access to many of these papers through your school system. If available, there may be some links to online sources of questions, though please be patient if the links are broken! (DrR: If you do find some broken links, please contact me through the site)

Questions on this topic (Section 7) are shown in dark purple.

Use this grid to practice past IB questions topic by topic. You can see from the colours how similar the question topic breakdown is year by year. The more you can familiarise yourself with the IB question style the better - eventually you will come to spot those tricks and types of questions that reappear each year.