An aluminum block and a polystyrene block are both kept at room temperature (≈20 ∘C\approx 20\ ^\circ\text{C}≈20 ∘C). A small, identical ice cube is placed on top of each block at the same time. The ice cube on the aluminum block melts very rapidly, whereas the ice cube on the polystyrene block melts extremely slowly. This experiment shows that, compared to polystyrene, aluminum is a good:
absorber of radiation.
conductor of heat.
emitter of radiation.
insulator of heat.
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.