The AQA A-level Physics Paper 3B (June 2023), Option D (Turning Points in Physics), focuses on significant historical advancements in physics, such as electron wave-particle duality, specific charge of the electron, and special relativity. Topics include JJ Thomson′s experiment, Millikan’s oil drop experiment, Newton’s corpuscular theory of light, and Einstein’s relativistic principles. Questions involve calculations of electron speed, electron diffraction, oil drop viscosity, and relativistic effects. The paper emphasizes experimental methods, theoretical analysis, and critical evaluation of classical and modern theories. Keywords: AQA Physics, turning points, wave-particle duality, electron charge, special relativity, JJ Thomson, Millikan experiment.