Led by Ernest Rutherford Simulacrum
About this course
A century ago nobody knew what was inside an atom. Today we routinely split atoms to generate electricity, fuse them in the sun to illuminate our planet, and use their emissions to image the insides of our own bodies. The physics that made this possible was worked out in about forty years by a small group of people working in a handful of laboratories — Cambridge, Paris, Manchester, Copenhagen, Berlin, Chicago. Early researchers worked without any understanding of the harms of ionising radiation and many paid with their health. The safety rules that govern modern nuclear medicine and power generation were built from their experience.
This course follows AQA specification 8463, section 4.4 in full, including the physics-only (triple-science) sections 4.4.3 and 4.4.4 on hazards, uses, and nuclear reactions. Six simulacra take the modules in turn. Bohr opens with the structure of the atom — his model of orbital energy levels is the one every student meets first. Rutherford takes the historical module on how the model was built up by experiment — his scattering experiment was the pivotal moment. Curie takes radioactive decay — she discovered the phenomenon and coined the word. Meitner takes half-lives and the random nature of decay — she spent three decades doing exactly this work. Feynman takes the physics-only module on hazards, uses, and background radiation — a clear, pragmatic voice on risk. Fermi closes the course with fission and fusion — he built the first nuclear reactor.
Higher-Tier content is flagged inline. Sections 4.4.3 and 4.4.4 are physics-only and sit in Modules 5 and 6 respectively.
Led by Niels Bohr Simulacrum
The question
What is an atom made of, how big is it, and what makes two atoms of the same element different?
Outcome
The student can describe the structure of the atom with correct relative sizes, explain electron energy levels and transitions, define atomic number, mass number, isotopes, and ions, and read the standard notation for a specified nuclide. (AQA 4.4.1.1, 4.4.1.2)
Led by Ernest Rutherford Simulacrum
The question
How does a scientific model change? Walk through the evidence that took us from "indivisible sphere" to "nucleus-with-electrons" in less than fifty years.
Outcome
The student can describe the sequence from indivisible sphere to plum pudding to nuclear model to Bohr model to neutron, explain why the alpha scattering experiment forced the change from plum pudding to nuclear, and articulate the principle that scientific models are provisional and change when new evidence arrives. (AQA 4.4.1.3)
Led by Marie Curie Simulacrum
The question
Some atomic nuclei spontaneously emit radiation. What are they emitting, and why?
Outcome
The student can name the four types of nuclear radiation, describe each in terms of composition, penetration, range, and ionisation, explain the difference between activity and count-rate, and write balanced nuclear equations for single alpha and beta decays. (AQA 4.4.2.1, 4.4.2.2)
Led by Lise Meitner Simulacrum
The question
If radioactive decay is a random process, how can it have a predictable half-life?
Outcome
The student can define half-life, determine it from a graph or table, (Higher Tier) calculate net decline as a ratio after a given number of half-lives, explain the difference between contamination and irradiation, and discuss why findings on radiation's biological effects must be peer-reviewed. (AQA 4.4.2.3, 4.4.2.4)
Led by Richard Feynman Simulacrum
The question
Radiation is genuinely dangerous and also genuinely useful. How do we think clearly about when to use it, what to protect against, and what "background" radiation actually is?
Outcome
The student can identify natural and man-made sources of background radiation, explain how occupation and location affect dose, reason about how half-life affects hazard, describe and evaluate the use of nuclear radiation in imaging and treatment, and weigh quantitative risk information against benefit. (AQA 4.4.3.1, 4.4.3.2, 4.4.3.3)
Led by Enrico Fermi Simulacrum
The question
You can get enormous amounts of energy either by splitting heavy nuclei apart or by forcing light nuclei together. How do these two processes work, and what is the same about them?
Outcome
The student can describe nuclear fission in full (with neutrons, products, energy release, and chain reaction), describe nuclear fusion, draw and interpret diagrams of a fission chain reaction, and articulate the difference between controlled (reactor) and uncontrolled (weapon) chain reactions. (AQA 4.4.4.1, 4.4.4.2)