Nuclear reactions

Nature of science:

Patterns, trends and discrepancies: Graphs of binding energy per nucleon and of neutron number versus proton number reveal unmistakable patterns. This allows scientists to make predictions of isotope characteristics based on these graphs. (3.1)

• The unified atomic mass unit
• Mass defect and nuclear binding energy
• Nuclear fission and nuclear fusion

Applications and skills:

• Solving problems involving mass defect and binding energy
• Solving problems involving the energy released in radioactive decay, nuclear fission and nuclear fusion
• Sketching and interpreting the general shape of the curve of average binding energy per nucleon against nucleon number

• The acceptance that mass and energy are equivalent was a major paradigm shift in physics. How have other paradigm shifts changed the direction of science? Have there been similar paradigm shifts in other areas of knowledge?

Utilization:

• Our understanding of the energetics of the nucleus has led to ways to produce electricity from nuclei but also to the development of very destructive weapons
• The chemistry of nuclear reactions (see Chemistry option sub-topics C.3 and C.7)

• Students must be able to calculate changes in terms of mass or binding energy
• Binding energy may be defined in terms of energy required to completely separate the nucleons or the energy released when a nucleus is formed from its nucleons

Data booklet reference:

• Aim 5: some of the issues raised by the use of nuclear power transcend national boundaries and require the collaboration of scientists from many different nations
• Aim 8: the development of nuclear power and nuclear weapons raises very serious moral and ethical questions: who should be allowed to possess nuclear power and nuclear weapons and who should make these decisions? There are also serious environmental issues associated with the nuclear waste of nuclear power plants.