IB Physics SL topic guide

The Particulate Nature of Matter

The Particulate Nature of Matter is a core part of IB Physics SL. This guide connects the syllabus ideas behind Specific Heat Capacity, Latent Heat, Heat Transfer Mechanisms, The Greenhouse Effect, Climate Feedbacks and Equilibrium Temperature and 4 more units, shows how they appear in worked problems, and points you to the formulas and full lessons needed for exam revision.

What you will learn

The Particulate Nature of Matter syllabus outline

The units below follow the structure used in the full Study to Learn course. Use the outline to identify exactly which idea needs attention, then work through the public example before continuing to the complete lesson path.

B.1

Specific Heat Capacity

Temperature, Heat and Internal Energy · Specific Heat Capacity — Calculations and Calorimetry · Heat Capacity and Thermal Equilibrium

B.2

Latent Heat

Phase Changes and Latent Heat · Heating Curves and Multi-Stage Problems

B.3

Heat Transfer Mechanisms

Conduction, Convection and Thermal Radiation · Blackbody Radiation — Stefan–Boltzmann and Wien's Laws

B.4

The Greenhouse Effect

The Greenhouse Effect · Modelling the Greenhouse Effect

B.5

Climate Feedbacks and Equilibrium Temperature

Modelling Earth's Equilibrium Temperature · Climate Feedback Loops

B.6

Ideal Gas Laws

Ideal Gas Laws · Units and Absolute Quantities

B.7

Kinetic Theory of Gases

Kinetic Theory · Maxwell-Boltzmann Distribution and Degrees of Freedom

B.9

DC Circuits

Current, Resistance and EMF · Series and Parallel Circuits · Potential Dividers and Sensors

B.10

Capacitors

Capacitance and Energy Storage · RC Circuits and Charging/Discharging

Free worked preview

Temperature, Heat and Internal Energy

This complete preview comes from the Specific Heat Capacity unit. It introduces the core language, shows the method in context, and gives you a real example of the lesson quality before you create an account.

Temperature, Heat and Internal Energy

Thermal physics begins not with equations but with careful definitions — the distinction between temperature, heat, and internal energy is one of the most commonly tested concepts in IB exams, precisely because students often conflate them. This foundational lesson equips you with the precise vocabulary that will carry you through specific heat capacity, latent heat, the ideal gas laws, and thermodynamics proper. When you finish, you will never again confuse a hot cup of tea's temperature with the far greater internal energy of a lukewarm swimming pool.
Reading the Notation You'll see a triangle Δ (capital Greek "delta") in front of many physics quantities throughout this course — it always means "change in", i.e. (final value − initial value). So ΔT means "change in temperature" = Tfinal − Tinitial, not "delta times T".

Small letters written after a symbol and slightly below the line (like the f in cf) are subscripts — they just label which version of a quantity you mean (e.g. cice = specific heat capacity of ice specifically, as opposed to cwater). They are not multiplied or exponents — they're just labels.

Three related but distinct ideas describe thermal physics:

QuantitySymbolMeaning
TemperatureTA measure of the average random kinetic energy of the particles in a substance. It determines the direction heat will flow (always hot → cold).
Heat / thermal energyQEnergy that is transferred between a system and its surroundings because of a temperature difference.
Internal energyUThe total energy stored inside a system: the sum of the random kinetic energies and the potential energies of all its particles.
Common MisconceptionTemperature is not the same thing as heat or internal energy. A cup of tea and a swimming pool can be at the same temperature, but the pool has vastly more internal energy because it has far more particles.

Converting Between Temperature Scales

T(K)=T(°C)+273.15T\text{(K)} = T(°\text{C}) + 273.15
where
T(K)T(K)temperature measured in kelvin (the SI unit — always use this in equations)
T(°C)T(°C)temperature measured in degrees Celsius

A change of 1°C is identical in size to a change of 1 K — only the zero point differs (0 K = absolute zero = −273.15°C). So ΔT is the same number whether you work in °C or K.

Reviewed by the Study to Learn editorial team · Updated 2026-07-24