Every definition and working formula from the six modules, gathered for revision. Fractions are stacked, exactly as you should write them. Keep energies in eV (keV for X-rays, MeV for nuclei) and use hc = 1240 eV·nm; unit help lives in the constants & conventions primer.
01 · Photoelectric Effect & Dual Nature
Photon — light arrives in quanta of energy E = hν = hc/λ and momentum p = h/λ. Work function φ — least energy to free an electron; emission needs ν ≥ ν₀ regardless of intensity.
Einstein's equation gives the maximum kinetic energy; the stopping potential V₀ measures it. de Broglie — every moving particle has a wavelength λ = h/p, so matter diffracts too.
Quantised orbits — angular momentum comes in units of h/2π, so only certain radii and energies are allowed. Energy is negative (bound) and rises toward zero as n grows.
Spectral series — a jump from n₂ to n₁ emits a photon set by the Rydberg formula; Lyman (n₁=1, UV), Balmer (n₁=2, visible), Paschen (n₁=3, IR). Hydrogen-like ions scale with Z².
Continuous spectrum — Bremsstrahlung with a sharp cutoff λ_min set only by the tube voltage (Duane–Hunt). Characteristic lines Kα, Kβ — inner-shell transitions fixed by the target element.
Moseley's law orders elements by nuclear charge Z. Bragg reflection lets a crystal diffract X-rays; only λ ≤ 2d can satisfy it.
Bands — a small gap E_g separates the valence and conduction bands; heat or doping supplies carriers. n-type (donors, majority electrons) and p-type (acceptors, majority holes) obey the mass-action law, staying neutral. Conductivity rises with T.
p–n junction — a one-way diode: forward bias conducts past the knee V_b, reverse bias blocks. Rectifiers make DC (full-wave ripple = 2f); transistor gains α, β amplify.
n_e·n_h = n_i²σ = e(n_eμ_e + n_hμ_h)V_b: Si 0.7, Ge 0.3 Vβ = α1 − αLED hν ≈ E_g
05 · The Nucleus & Radioactivity
Size — radius grows as A^(1/3), so nuclear density is nearly constant. Binding energy comes from the mass defect (Δm·c²); the B/A curve peaks near iron, so fusion of light nuclei and fission of heavy ones both release energy.
Radioactivity — α, β, γ emissions; the number left decays exponentially, with activity A = λN and half-life t½ = 0.693/λ.
Two postulates — the laws of physics are the same in every inertial frame, and light travels at c for everyone. Everything follows through the Lorentz factor γ ≥ 1.
Time dilation (moving clocks run slow) and length contraction (moving rulers shrink along the motion) are reciprocal. Velocities add so nothing beats c, and mass is energy: E = γm₀c².