Essential idea: The idea of discreteness that we met in the atomic world continues to exist in the nuclear world as well.
Nature of science:
Theoretical advances and inspiration: Progress in atomic, nuclear and particle physics often came from theoretical advances and strokes of inspiration.
Advances in instrumentation: New ways of detecting subatomic particles due to advances in electronic technology were also crucial.
Modern computing power: Finally, the analysis of the data gathered in modern particle detectors in particle accelerator experiments would be impossible without modern computing power. (1.8)
Understandings:
Rutherford scattering and nuclear radius
Nuclear energy levels
The neutrino
The law of radioactive decay and the decay constant
Applications and skills:
Describing a scattering experiment including location of minimum intensity for the diffracted particles based on their de Broglie wavelength
Explaining deviations from Rutherford scattering in high energy experiments
Describing experimental evidence for nuclear energy levels
Solving problems involving the radioactive decay law for arbitrary time intervals
Explaining the methods for measuring short and long half-lives
Guidance:
Students should be aware that nuclear densities are approximately the same for all nuclei and that the only macroscopic objects with the same density as nuclei are neutron stars
The small angle approximation is usually not appropriate to use to determine the location of the minimum intensity
Data booklet reference:
Theory of knowledge:
Much of the knowledge about subatomic particles is based on the models one uses to interpret the data from experiments. How can we be sure that we are discovering an “independent truth” not influenced by our models? Is there such a thing as a single truth?
Utilization:
Knowledge of radioactivity, radioactive substances and the radioactive decay law are crucial in modern nuclear medicine (see Physics option sub-topic C.4)
Aims:
Aim 2: detection of the neutrino demonstrates the continuing growing body of knowledge scientists are gathering in this area of study