Cambridge IGCSE Physics Notes 2.2: Thermal Properties and Temperature

Q: What does Cambridge IGCSE Physics Notes 2.2: Thermal Properties and Temperature cover?
A: It follows official Cambridge Physics section 2.2 for syllabuses 0625 and 0972, with Core ideas separated from Supplement depth.

Thermal properties describe how materials expand, store internal energy, and change state when energy is transferred.

The ideas that organise this section

• Thermal expansion follows increased particle separation, not particle growth.
• Specific heat capacity measures energy needed per unit mass per unit temperature rise.
• Evaporation occurs at the surface and causes cooling because higher-energy particles escape.

Core route

Core candidates should be ready to describe, calculate, interpret, and apply the following:

• Describe expansion and its applications or hazards.
• Explain melting, boiling, evaporation, and cooling using particles.
• Compare thermometer sensitivity, range, and linearity in context.

Supplement route

Extended candidates study all Core content and add the following depth:

• Calculate energy changes using mass, specific heat capacity, and temperature change.
• Explain evaporation rate using temperature, surface area, and air movement.
• Interpret heating and cooling behaviour where energy changes internal energy without changing temperature during a state change.

Formula route

• Relationship: energy transferred = mass x specific heat capacity x temperature change.

Write the relationship before substituting. Convert units first, keep extra figures during working, and round only the final answer to sensible precision.

Build a connected model

In Thermal Properties and Temperature, a strong answer connects the named quantity or model to observable evidence. Begin by defining the physical quantity in words or with its relationship. Identify which values are scalars and which require a direction. Represent the situation with a labelled diagram, graph, field pattern, ray or circuit when that makes the relationship visible. The representation is part of the reasoning: its labels, arrows and scale should agree with the written explanation.

For a calculation, write the governing relationship before substitution, convert prefixes and time units, keep unrounded values during working and attach the correct final unit. For a qualitative question, use a cause-link-consequence chain. Name what changes, state the physical mechanism that links the change to the system, and then give the measurable result. If two cases are compared, hold unrelated variables constant and use the same physical principle for both.

Check the answer against limiting cases. A zero input, a doubled input or a reversed direction often exposes an incorrect proportionality or sign. Also check whether the value is plausible for the apparatus or context. This final check is especially important when a calculator gives a precise-looking result from an incorrect unit conversion.

Worked reasoning example

Water is useful as a coolant because its high specific heat capacity allows it to absorb substantial energy for a modest temperature rise.

For explanation questions, state the physical principle, apply it to the named system, then give the consequence. A formula or keyword by itself is not a complete explanation.

Extend the example by identifying the evidence that would distinguish the correct model from a tempting alternative. State what would be measured or observed, which variable must remain controlled, and how the conclusion follows from the result. This turns a numerical or descriptive answer into a testable physical argument. When the question asks for an explanation rather than a calculation, preserve the same chain but express it as principle, application and consequence.

A reliable answer method

1. Identify the quantity, law, graph feature, or physical model being tested.
2. Mark a positive direction or label the diagram when direction matters.
3. Write the equation or principle before inserting data.
4. Keep units consistent and show the main substitution.
5. Check whether the magnitude, direction, trend, and unit are physically reasonable.

Common mistakes

• Using final temperature instead of temperature change.
• Treating boiling and evaporation as identical processes.
• Saying temperature rises throughout melting.

Assessment guidance

Questions on Thermal Properties and Temperature can mix recall, calculation, graph or diagram interpretation and unfamiliar application. Read the command word first. A definition needs the precise physical meaning; a description reports a pattern; an explanation supplies the mechanism; and an evaluation weighs evidence or method quality. Show equations and substitutions so method marks remain visible. Label every diagram and state directions where relevant. In multi-step problems, carry forward unrounded values and make the final answer's unit and significant figures consistent with the data. Never rely on a memorised keyword when the question asks how or why a result occurs.

Retrieval practice

Without notes, rebuild the Core and Supplement lists for Thermal Properties and Temperature. Define every named quantity, reproduce the principal relationship or representation and explain one everyday application. Then solve one direct calculation and one unfamiliar context, checking units and limiting cases. Finish by writing two misconception corrections and one practical measurement that could test the topic's main relationship.

Theory and practical stay separate

Use the thermal-investigations post for heater methods, insulation, temperature-time graphs, and heat-loss evaluation.

• Cambridge IGCSE Physics theory hub
• Cambridge IGCSE Physics practical hub
• Physics 0625 study plan

Official source

Cambridge International, Physics 0625 syllabus for examinations in 2026, 2027 and 2028. Cambridge states that Physics 0972 is graded from 9 to 1 but otherwise follows the same subject content as 0625.