IB Physics — Syllabus & Revision Notes
BETADiploma Programme Physics, 2025-2030 syllabus (first assessment 2025) — the five themes A–E with every topic and subtopic, tagged for Standard and Higher Level.
What is IB Physics?
IB Physics is one of the Diploma Programme’s group 4 science subjects: a two-year course taken at either Standard Level (SL) or Higher Level (HL) and examined at the end of the second year. The 2025-2030 syllabus (first exams 2025) organises the subject into five themes — space, time and motion; the particulate nature of matter; wave behaviour; fields; and nuclear and quantum physics — studied alongside practical work and an independent investigation.
SL and HL follow the same five themes, but HL goes further: five topics are HL-only (rigid body mechanics, Galilean and special relativity, thermodynamics, induction and quantum physics) and seven shared topics carry additional HL material — roughly 180 hours of taught content at HL against 110 at SL. SL and HL candidates sit separate exam papers: HL papers mix the extra material throughout, while SL papers draw only on SL content. Both levels are graded 1–7, and every paper is sat with the official data booklet of formulae on the desk — so revision is less about memorising equations and more about knowing how to use them.
| Assessment | SL | HL | Weight |
|---|---|---|---|
| Paper 1 — 1A multiple choice + 1B data analysis | 45 marks · 1h 30 | 60 marks · 2h | 36% |
| Paper 2 — short and extended response | 50 marks · 1h 30 | 90 marks · 2h 30 | 44% |
| Internal assessment — your own scientific investigation | marked by your teacher, samples checked by the IB | 20% | |
The syllabus map below lists every topic and subtopic with its level badge — SL & HL shared, SL & HL +HL with HL extensions, HL only for the five HL topics. Each topic links to revision notes with formulae in the data booklet’s own notation, and pages with HL material have an SL/HL switch so you only revise what your paper can ask.
A Space, Time and Motion
- Distance, displacement, speed and velocity
- Acceleration and motion graphs
- Equations of motion (SUVAT)
- Projectile motion
- Fluid resistance and terminal speed
- Newton's three laws of motion
- Forces and free-body diagrams
- Friction and contact forces
- Circular motion and centripetal force
- Momentum and impulse
- Conservation of momentum; collisions and explosions
- Work done by a force
- Kinetic, gravitational and elastic potential energy
- Conservation of mechanical energy
- Power and efficiency
- Energy density of fuel sources
- Torque and rotational equilibrium
- Moment of inertia
- Newton's second law for rotation
- Angular momentum and its conservation
- Rotational kinetic energy
- Reference frames and Galilean relativity
- The postulates of special relativity
- Lorentz transformations
- Time dilation and length contraction
- Spacetime diagrams and the relativity of simultaneity
B The Particulate Nature of Matter
- Molecular theory of solids, liquids and gases
- Temperature, internal energy and the Kelvin scale
- Specific heat capacity
- Phase changes and latent heat
- Conduction, convection and thermal radiation
- Black-body radiation and emissivity
- Albedo and Earth's energy balance
- The solar constant
- Greenhouse gases and infrared absorption
- The enhanced greenhouse effect
- Pressure and amount of substance (moles)
- The empirical gas laws
- The ideal gas law
- Kinetic theory of an ideal gas
- Internal energy of an ideal gas
- The first law of thermodynamics
- Thermodynamic processes (isobaric, isothermal, adiabatic, isovolumetric)
- Entropy and the second law of thermodynamics
- Heat engines and efficiency
- The Carnot cycle
- Electric current and charge
- Potential difference and emf
- Resistance, resistivity and Ohm's law
- Ohmic and non-ohmic conductors
- Electrical power and energy
- Resistors in series and parallel
C Wave Behaviour
- Conditions for simple harmonic motion
- Period, frequency and angular frequency
- Mass-spring systems and pendulums
- Energy in simple harmonic motion
- SHM equations and phase angle (HL)
- Transverse and longitudinal waves
- Wavelength, frequency, period and wave speed
- Sound waves
- Electromagnetic waves
- Reflection and refraction; Snell's law
- Total internal reflection and the critical angle
- Diffraction
- Superposition and interference
- Young's double-slit interference
- Single-slit diffraction and diffraction gratings (HL)
- Formation of standing waves
- Nodes, antinodes and harmonics
- Standing waves in strings and pipes
- Resonance and natural frequency
- Damping
- The Doppler effect for sound and light
- Wavefront diagrams for a moving source or observer
- Doppler shift of spectral lines (astronomy)
- Quantitative Doppler effect for sound (HL)
D Fields
- Newton's law of gravitation
- Gravitational field strength
- Orbital motion and Kepler's laws
- Gravitational potential and potential energy (HL)
- Escape speed and orbital energy (HL)
- Electric charge and Coulomb's law
- Electric field strength and field lines
- Uniform fields between parallel plates
- Magnetic fields and field lines
- Electric potential and potential energy (HL)
- Equipotential surfaces (HL)
- Charged particles in a uniform electric field
- Charged particles in a uniform magnetic field
- Force on a moving charge (combined electric and magnetic fields)
- Force on a current-carrying conductor
- Force between parallel current-carrying wires
- Magnetic flux and flux linkage
- Faraday's law of electromagnetic induction
- Lenz's law
- Motional emf (a conductor moving in a field)
- emf from a coil rotating in a magnetic field
E Nuclear and Quantum Physics
- The nuclear atom and the Rutherford scattering experiment
- Nuclear notation
- Atomic energy levels and spectra
- Photon emission and absorption in transitions
- Nuclear radius and deviations from Rutherford scattering (HL)
- The Bohr model for hydrogen (HL)
- The photoelectric effect
- Einstein's photoelectric equation and the work function
- Matter waves and the de Broglie wavelength
- Wave-particle duality
- Compton scattering
- Isotopes, mass defect and nuclear binding energy
- Mass-energy equivalence (E = mc^2)
- The strong nuclear force
- Alpha, beta and gamma decay; decay equations
- Half-life, activity and count rate
- The radioactive decay law and decay constant (HL)
- Nuclear fission and energy release
- Chain reactions
- Nuclear reactors (control rods, moderators, shielding)
- Fission products and nuclear waste
- Nuclear fusion in stars
- Stellar equilibrium
- Conditions for fusion and stellar evolution
- The Hertzsprung-Russell diagram
- Stellar parallax, luminosity and radii