Chapter 43: Nuclear Physics

The content explores nuclear binding energy through mass-energy equivalence calculations and introduces two complementary nuclear models: the liquid-drop model, which uses thermodynamic analogies to estimate binding energies through volume, surface, Coulomb, asymmetry, and pairing terms, and the shell model, which explains nuclear stability through magic numbers and electron-like orbital configurations. The chapter thoroughly investigates radioactive decay processes, including alpha decay involving helium nuclei emission, beta-minus decay where neutrons convert to protons with electron and antineutrino production, beta-plus decay and electron capture for proton-to-neutron conversions, and gamma decay for nuclear de-excitation. Quantitative analysis of decay kinetics introduces exponential decay laws, activity measurements, half-life calculations, and radiocarbon dating applications. The biological impact of radiation exposure is examined through absorbed dose measurements in grays, equivalent dose calculations using quality factors, and medical applications in imaging and cancer treatment. Nuclear reactions are analyzed using conservation laws and Q-value calculations to determine energy release or requirements. The chapter concludes with detailed coverage of nuclear fission in uranium-235, including chain reaction mechanics, reactor control systems using moderators and control rods, and nuclear fusion processes powering stellar nucleosynthesis and potential terrestrial energy applications through magnetic confinement tokamaks and inertial confinement laser systems.