Playbook
Thermal Properties of Matter
84 q - 2.13/paper - 17% HARD. 53 of the 84 are radiation — Stefan and Wien as ratio questions.
- Questions in the bank
- 84
- q/paper (2024–25 papers)
- 2.13
- Tagged HARD
- 17%
- Subtopics
- 4
Strand: Long Tail
When you’ll see it
A hot body radiating, a black body and its peak wavelength, a body cooling, a rod or plate expanding, or heat flowing through a slab.
How this chapter is tested
84 q at 2.13 a paper, 17% HARD — and on this paper the chapter is mostly radiation: Radiation — Stefan, Wien, Newton's Law of Cooling, Black Body is 53 of the 84 questions at 23% HARD.
Almost every radiation question is a ratio. Stefan: P = σAeT⁴, so doubling the absolute temperature multiplies the power by 16. Wien: λ_max T = constant, so a hotter body peaks at a shorter wavelength. Newton's law of cooling: the rate of cooling is proportional to the excess temperature, used with the average temperature over an interval.
Thermal expansion (19 q, 11%) is β = 2α and γ = 3α. Conduction (8 q) and calorimetry (4 q) are small and have never produced a HARD question.
The sub-skills
The distinct skills inside the chapter, in the order to learn them.
Stefan–Boltzmann
P = σAeT⁴ with T in kelvin. Net loss to surroundings ∝ T⁴ − T₀⁴.
Wien's law
λ_max T = b ≈ 2.9 × 10⁻³ m K.
Newton's law of cooling
(T₁ − T₂)/t = k[(T₁ + T₂)/2 − T₀]. Use it twice and take the ratio.
Expansion
ΔL = LαΔT; area β = 2α; volume γ = 3α.
Traps to expect
Distractor shapes this chapter reuses. The Traps page covers the patterns that cut across chapters.
Using Celsius in Stefan's law
T⁴ needs kelvin. 227 °C to 727 °C is 500 K to 1000 K: power ×16, not ×(727/227)⁴.
Forgetting the surroundings
A body in a room at T₀ loses net power σAe(T⁴ − T₀⁴). Using T⁴ alone overstates the loss.
Learn it before you drill it
This chapter has full teaching notes — foundations, worked examples, self-checks and a per-subtopic mastery checkpoint. Read the notes once, then drill subtopic by subtopic below.
Thermal Properties of Matter notesDrill every thermal properties of matter question
84 questions from the bank, scoped to 4 bundled subtopics.
Drill one subtopic at a time
The 4 subtopics this playbook covers, in catalog order.
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