Two identical copper blocks, one coated in matte black paint and the other with a polished shiny silver surface, are suspended inside a vacuum chamber. Both blocks are initially at a temperature of 80∘C80^\circ\text{C}80∘C, which is much warmer than the walls of the chamber.
Which statement correctly describes how the temperatures of the blocks change over time?
Both blocks remain at 80∘C80^\circ\text{C}80∘C because heat cannot transfer through a vacuum.
The polished silver block cools down more quickly than the matte black block.
The matte black block cools down more quickly than the polished silver block.
Both blocks cool down at the same rate.
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.