7081. On a cold day when a room temperature is 15oC, the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of 15oC, because September 20, 2025 by Admin A. metals have higher thermal capacity than plastics B. plastics have a lower density than metals C. metals are good conductor of heat D. plastics have a higher thermal conductivity than metals ✅ The correct answer is option C.