You are presented with the question "What is the result of imperfect passing of heat through a metal, on that metal?" and the following answer choices: 
- contamination
 - expansion
 - sweating
 - Energy.
 - forces
 - burning
 - Evaporation
 - electricity

Now knowing that when metal conducts heat , that metal expands and conduction is the passing of heat through a medium, choose the best answer.


 

  expansion       