CIE iGCSE Co-Ordinated Science P2.3.1 Conduction Exam Style Questions Paper 2
▶️ Answer/Explanation
Thermal conduction in solids occurs via lattice vibrations (phonons) in all solids, but metals also have delocalised electrons that transfer energy rapidly. Therefore, lattice vibrations occur in both metals and plastics, while electron movement is mainly in metals. Thus row C is correct.
✅ Answer: (C)
✅ Answer: (C)
▶️ Answer/Explanation
Metals contain free (delocalised) electrons that can move freely through the metal lattice.
These electrons gain kinetic energy at the hot end and transfer it quickly through the metal by colliding with other electrons and ions.
Non-metals lack these free electrons, so they can only transfer energy by slower atomic vibrations.
✅ Answer: (C)
These electrons gain kinetic energy at the hot end and transfer it quickly through the metal by colliding with other electrons and ions.
Non-metals lack these free electrons, so they can only transfer energy by slower atomic vibrations.
✅ Answer: (C)
▶️ Answer/Explanation
In grilling, thermal energy travels through the air from the red-hot heater to the food by infrared radiation, since air is a poor conductor.
In frying, thermal energy passes through the solid metal pan by conduction, as vibrating particles pass energy to neighbouring particles.
✅ Answer: (C)
In frying, thermal energy passes through the solid metal pan by conduction, as vibrating particles pass energy to neighbouring particles.
✅ Answer: (C)
▶️ Answer/Explanation
In all solids, particles vibrate about fixed positions and pass energy to neighbouring particles by collisions, so option B occurs in all solids, not just metals.
Metals additionally contain free (delocalised) electrons that can move through the structure, carrying thermal energy much more quickly than vibrations alone.
This free movement of electrons, described in option C, is the process unique to metals and explains why metals are much better thermal conductors than non-metals.
✅ Answer: (C)
Metals additionally contain free (delocalised) electrons that can move through the structure, carrying thermal energy much more quickly than vibrations alone.
This free movement of electrons, described in option C, is the process unique to metals and explains why metals are much better thermal conductors than non-metals.
✅ Answer: (C)
▶️ Answer/Explanation
The worst conductor of heat will have the lowest final temperature at the other end, as heat is conducted poorly through it. Rod A has the lowest final temperature (50°C), meaning it is the worst conductor. Good conductors would reach higher temperatures at the far end.
✅ Answer: (A)
✅ Answer: (A)