Who this is for: Cambridge IGCSE Coordinated Science (0654) students who want thermal processes — conduction, convection and radiation — to become a reliable source of marks in describe and explain questions.
What query it owns: how to understand and revise thermal processes in Cambridge IGCSE Coordinated Science.
Why this is safe: this page owns the thermal processes revision-guide angle, while Tutopiya’s Thermal Processes subtopic page owns the learning resource and the free Thermal Processes quiz owns the practice.

Thermal processes are the three ways energy is transferred by heating: conduction (through solids), convection (through fluids by movement), and radiation (infrared waves, no medium needed). Cambridge IGCSE Coordinated Science (0654) expects you to describe each process, give everyday examples, and explain insulation. This guide maps each transfer method to the describe and explain questions examiners set.

Key takeaways

• Conduction: energy transferred through a material without bulk movement; best in metals (free electrons).
• Convection: energy transferred by movement of heated fluid (liquid or gas); hot fluid rises, cool fluid sinks.
• Radiation: energy transferred by infrared electromagnetic waves; works through a vacuum.
• Good conductors: metals; good insulators: foam, fibreglass, trapped air.
• Shiny surfaces are poor emitters and absorbers of radiation.

What are thermal processes in Cambridge IGCSE Coordinated Science?

When two objects at different temperatures are in contact, energy transfers from the hotter to the cooler until they reach thermal equilibrium. Conduction occurs mainly in solids as vibrating particles pass energy to neighbours — metals also use free electrons. Convection requires a fluid: heated fluid expands, becomes less dense, and rises, carrying energy with it. Radiation is the only method that works in a vacuum, such as energy from the Sun reaching Earth. Examiners test whether you can match each process to real examples.

Read the full notes and diagrams on Tutopiya’s Thermal Processes subtopic page before attempting past-paper questions.

Comparing conduction, convection and radiation

Process	Medium needed?	How energy transfers	Example
Conduction	Solid (or stationary fluid)	Particle vibration / electron movement	Metal pan handle heats up
Convection	Fluid (liquid or gas)	Bulk movement of heated fluid	Hot air rising from a radiator
Radiation	None (works in vacuum)	Infrared electromagnetic waves	Sun warming the Earth

Insulation and reducing heat transfer

Method	Process reduced	How it works
Cavity wall insulation (foam/fibre)	Conduction + convection	Trapped air is a poor conductor
Double glazing	Conduction + convection	Air gap between panes
Aluminium foil / shiny surfaces	Radiation	Reflects IR radiation
Vacuum flask	All three	Vacuum stops conduction/convection; silvered surfaces reduce radiation

Thermal processes in past-paper wording: command words that matter

Command word / phrase	What the question wants	Typical thermal processes stem
Describe	Name and explain process	”Describe how convection transfers energy in a liquid.”
Explain	Apply to a situation	”Explain why a metal spoon gets hot in a cup of tea.”
State	Name a process	”State the three methods of thermal energy transfer.”
Suggest	Apply insulation knowledge	”Suggest how to reduce heat loss from a house.”

Worked exam-style stems (how to answer the wording)

1. “Describe how energy is transferred by convection in a liquid.” The liquid at the bottom is heated, expands, becomes less dense, and rises; cooler, denser liquid sinks to take its place, creating a convection current that transfers energy throughout the liquid. Reward: heated fluid rises + cooler fluid sinks + convection current.
2. “Explain why energy from the Sun reaches the Earth through empty space.” Energy is transferred by radiation (infrared/electromagnetic waves), which does not require a medium and can travel through a vacuum. Reward: radiation + no medium needed.
3. “Explain why metals are good conductors of thermal energy.” Metals contain free electrons that can move through the structure and carry kinetic energy quickly from hot regions to cold regions, in addition to particle vibration. Reward: free electrons + carry energy quickly.

Test yourself with the Thermal Processes quiz once you can describe all three processes and explain insulation.

How thermal processes connect to the rest of Coordinated Science

Thermal processes build on Matter And Thermal Properties and link to Measurement Of Temperature. Radiation connects forward to the Electromagnetic Spectrum. The Cambridge IGCSE Coordinated Science resource hub links every Thermal Physics subtopic.

Common mistakes students make

• Saying convection occurs in solids (requires fluid movement — liquids and gases only).
• Describing radiation as needing a medium (it works through a vacuum).
• Confusing conduction (no bulk movement) with convection (bulk movement of fluid).
• Forgetting that shiny surfaces are poor emitters and absorbers of radiation.
• Saying insulators stop all heat transfer (they reduce the rate, not eliminate it).

When you need more support

If thermal process questions keep costing marks, work through the Thermal Processes quiz, then get focused help from a Cambridge IGCSE Coordinated Science tutor.

Frequently asked questions

What are the three methods of thermal energy transfer? Conduction, convection and radiation.

Which method works in a vacuum? Radiation — infrared electromagnetic waves do not need a medium.

Why are metals good conductors? Free electrons move through the structure and carry kinetic energy quickly.

How do I revise thermal processes effectively? Learn the comparison table, practise describe and explain stems, then take the quiz.

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