Which statement about the methods of thermal energy transfer is correct?
Conduction in metals is primarily due to the physical movement of metal atoms from the hot end to the cold end.
Convection currents rise in a fluid because the heated fluid expands and its density decreases.
Thermal radiation is the only method of heat transfer that requires a material medium to travel.
A vacuum is an excellent conductor of heat because there are no molecules to absorb the energy.
301 exam-style questions on CIE IGCSE Physics 2.3 Transfer of thermal energy, covering 2.3.1a Thermal conductors and thermal insulators, 2.3.1b Explaining thermal conduction, 2.3.2 Convection, 2.3.3a Thermal radiation, 2.3.3b Surface colour and texture, 2.3.3c Rate of emission and absorption of radiation, and 2.3.4 Consequences of thermal energy transfer. Each one has a worked solution and a mark scheme showing where the marks go.