Unit 19
Nuclear chemistry
Chemical reactions move electrons; nuclear reactions change the nucleus itself, with energies a million times larger. In this unit you draw the chart of nuclides and the binding-energy curve from the NUBASE2020 and AME2020 evaluations, follow the uranium series with the Bateman equations, date rocks and artefacts from isotope ratios, and finally compare fission, fusion and chemical fuels — and learn to read becquerels, grays and sieverts.
- 1 Nuclear stability and binding energy Of more than 3500 known nuclides only 253 are stable. The band of stability, the magic numbers and the binding-energy curve tell you why — and why iron and nickel sit at the top of the curve. 30 min
- 2 Radioactive decay α, β⁻, β⁺, electron capture and γ: five ways a nucleus moves toward stability. Balance decay equations, count the steps from uranium-238 to lead-206, and watch individual nuclear “dice” add up to the exponential law. 30 min
- 3 Half-life and radiometric dating Radioactive decay is the most reliable clock there is: carbon-14 for tens of thousands of years, potassium–argon and uranium–lead for billions. Compute ages from isotope ratios and meet the hidden assumptions — calibration and closed systems. 25 min
- 4 Fission, fusion and radiation dose Fully fissioning one kilogram of uranium-235 releases as much energy as burning one and a half million kilograms of methane. Compute fission and fusion energies from mass defects, and meet chain reactions, medical isotopes and the real magnitudes of Bq, Gy and Sv. 30 min