Which of the following describes the main reason why metals are much better conductors of thermal energy than non-metals?
Convective currents of fluid ions transfer heat within the solid.
Free (delocalized) electrons rapidly transfer kinetic energy through the metal lattice.
The atomic nuclei in metals have a lower mass, allowing them to vibrate more easily.
Radiation from the surface of metals transfers thermal energy without physical contact.
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.