Mechanics is the largest topic and appears in every paper. Free-body diagrams must show all forces with correct direction and label — missing one force loses all method marks for that question.

• Kinematics: displacement, velocity, acceleration, SUVAT equations
• Newton's Laws: forces, free-body diagrams, friction
• Work, energy and power: conservation of energy, efficiency
• Momentum and impulse: conservation, collisions (elastic/inelastic)
• Circular motion: centripetal force, period and frequency
• Gravitational fields: Newton's Law of Gravitation, orbital mechanics

Ideal gas calculations require correct SI units — pressure in Pa, volume in m³, temperature in K. For HL, thermodynamic cycles (Carnot, heat pumps) appear with entropy calculations.

• Temperature and internal energy
• Specific heat capacity and latent heat calculations
• Ideal gas law: pV = nRT
• Kinetic theory: pressure, rms speed
• Thermodynamic processes (isothermal, adiabatic, isobaric)

Interference and diffraction questions require path difference reasoning: constructive interference when path difference = nλ; destructive when = (n + ½)λ. The diffraction grating equation dsinθ = nλ appears in every exam cycle.

• Wave properties: amplitude, frequency, wavelength, wave speed
• Transverse vs longitudinal waves
• Superposition and interference (constructive/destructive)
• Standing waves: nodes and antinodes
• Diffraction (single slit, double slit, diffraction grating)
• Doppler effect
• Refraction and total internal reflection

For circuit questions, redraw the circuit first before applying Kirchhoff's Laws. Electromagnetic induction questions test both quantitative (calculate EMF) and qualitative (state direction of induced current using Lenz's Law) skills.

• Coulomb's Law and electric fields
• Electric potential and potential energy
• Current, voltage, resistance (Ohm's Law)
• Series and parallel circuits, internal resistance
• Capacitance: charge, energy stored
• Magnetic fields: force on moving charges and current-carrying conductors
• Electromagnetic induction: Faraday's and Lenz's Laws
• Alternating current and transformers (HL)

Binding energy per nucleon graphs are tested in every exam — know the shape (iron peak at ~8.8 MeV/nucleon) and be able to explain why fission and fusion both release energy. The photoelectric equation hf = Φ + ½mv²_max is always tested quantitatively.

• Radioactive decay: alpha, beta, gamma properties and penetration
• Half-life calculations and decay equations
• Nuclear reactions: fission, fusion, binding energy per nucleon
• Mass-energy equivalence: E = mc²
• Photoelectric effect: threshold frequency, work function, Einstein's equation
• Wave-particle duality: de Broglie wavelength
• Atomic spectra: emission and absorption lines