Cambridge IGCSE Physics · Syllabus 0625 · Thermal Physics
Thermal Expansion
What is Thermal Expansion?
Thermal expansion is the increase in the volume, and usually the length, of a substance when its temperature rises at constant pressure; it happens because the particles move over a greater range so that their average separation increases, while the particles themselves do not change size.
This definition is part of the Thermal Physics chapter in Cambridge IGCSE Physics.
Thermal Expansion in context
Topic 2 of Cambridge IGCSE Physics 0625 contains 45 printed statements: 24 Core, taught to all candidates, and 21 Supplement, taught in addition to Core for candidates following the Extended route. The Core statements cover the kinetic particle model and states of matter, Brownian motion as evidence for that model, gas pressure and the qualitative gas relationships, the kelvin scale, thermal expansion and its applications, internal energy, changes of state and evaporation, and thermal energy transfer by conduction, convection and infrared radiation with basic everyday applications. The Supplement statements add inter-particle forces, force per unit area in gases, \(pV = \text{constant}\), the particle explanation of expansion, average kinetic energy and specific heat capacity with its two experiments, the boiling–evaporation comparison and evaporative cooling of an object, the mechanisms and limits of conduction, the radiation balance including the Earth's temperature, emitter and absorber experiments, and complex multi-route applications.